Heparan sulfate sulfatase deficiency

Related Terms

Acetyl-CoA alpha-glucosaminide N-acetyltransferase deficiency, glycosaminoglycans, heparan sulfate, heparan sulfate sulfatase deficiency, lysosomal storage disease, MPS III, MPS type 3, mucopolysaccharides, mucopolysaccharidosis III, mucopolysaccharidosis type 3, N-acetylglucosamine-6-sulfate sulfatase deficiency, N-acetylglucosaminidase deficiency.

Background

Sanfilippo syndrome is an inherited disease that belongs to a group of diseases called mucopolysaccharidoses (MPS). Specifically, it is known as MPS type 3. Mucopolysaccharides are complex sugar molecules that are constantly used and broken down in the body. In 1963, Dr. Sylvester Sanfilippo was one of the first doctors to describe Sanfilippo syndrome.
In individuals with Sanfilippo syndrome, one of the enzymes that break down heparan sulfate, a carbohydrate, or complex sugar molecule, that inhibits blood clotting, is missing or malfunctioning. This causes heparan sulfate to buildup to abnormally high levels in lysosomes, which are the compartments in the cell responsible for breaking down and disposing of cell waste. Waste products that buildup in lysosomes are excreted in the urine, so individuals with Sanfilippo syndrome tend to have high levels of heparan sulfate in their urine.
Because of the buildup of heparan sulfate, cells do not function properly. Symptoms of Sanfilippo syndrome include problems with the heart, bones, joints, and lungs. As the disease progresses, this buildup of heparan sulfate in nerve cells causes serious problems resulting from the failure of the nervous system.
It is estimated that Sanfilippo syndrome affects one out of every 80,000 births. Males and females are affected in equal numbers. The disease may not be apparent at birth. Signs and symptoms progress with age as heparan sulfate accumulates and damages cells and organs. Most people with Sanfilippo syndrome live into their teenage years. Some patients live longer, while others with severe forms die at an earlier age from complications.
There are four types of Sanfilippo syndrome: types A, B, C, and D. Each type is caused by mutations in one of the four genes that provide instructions for making enzymes involved in breaking down heparan sulfate. Depending on the type of Sanfilippo syndrome, the mutation could occur in the gene for heparan sulfate sulfatase (type A), alpha-N-acetylglucosaminidase (type B), acetyl-CoA alpha-glucosaminide N-acetyltransferase (type C), or N-acetylglucosamine 6-sulfatase (type D).

Signs and symptoms

General: The symptoms of Sanfilippo syndrome generally appear between the ages of two and six. The majority of patients develop symptoms by four years of age. The disorder usually progresses slowly.
Developmental problems: Initially the child appears normal, but then starts to fall behind in developmental areas such as walking and talking. Behavioral problems are common and may include hyperactivity, aggressiveness, and restlessness. Early progress in language and understanding is lost as a severe learning disability develops. Delayed development is followed by deteriorating mental status. From age five to 10, the difficult behavior and hyperactivity progress.
The child may have normal growth during the first few years of life, but the final height is below average. After age 10, people with Sanfilippo syndrome physically slow down, gradually lose movement skills, balance, and coordination, and develop tremors.
Physical features: There may be physical features such as an enlarged head, full lips, and heavy eyebrows that meet in the middle of the face above the nose. Bone density is usually lower than normal. However, many children with Sanfilippo syndrome do not have these symptoms.
Other: Other symptoms may include diarrhea, incontinence, speech and hearing impairment, constant runny nose, hernia, heart disease, depression, pain, and stiff joints that may not extend fully. Tumors may form on the retina (i.e., the back of the eye).

Diagnosis

Audiogram: An audiogram, or hearing test, may help diagnose hearing loss. During an audiogram, the patient wears headphones and is exposed to various sounds that have different pitches and frequencies. The patient is asked to identify each time a sound is heard. The audiologist may also say various words to evaluate the patient's hearing ability.
Biopsy: Once tumors are identified, a biopsy may be performed to determine whether they are cancerous. A small tissue sample is taken from the patient and analyzed under a microscope to determine whether cancerous cells are present.
Blood tests: Blood can be drawn, or samples of cells from the skin may be taken and grown, to test for abnormal heparan sulfate-related enzyme levels.
Echocardiogram: An echocardiogram, which uses sound waves to create a moving picture of the heart, can be used to test for abnormal heart rhythms.
Eye exam: During an eye exam, a slit lamp test may be performed to determine whether there are tumors on the retina. The slit lamp is a microscope with a light that helps the eye doctor observe the eye under high magnification. The doctor is able to see the front and the back of the eye.
Genetic testing: Genetic testing is available only through research institutions studying the disorder. A sample of the patient's blood is analyzed in a laboratory for the presence of a mutated gene. A total of 62 mutations have now been identified for Sanfilippo type A, and 86 mutations for Sanfilippo type B. For these types, many of the reported mutations are unique, making screening in the general population difficult. However, examination of DNA from patients with Sanfilippo type A has revealed a high incidence of particular mutations of different geographical origins, which may be beneficial for future diagnoses of Sanfilippo type A.
If there is a family history of Sanfilippo syndrome, prenatal genetic testing may be offered to determine whether a patient's fetus has the disorder. However, testing is not widely available, and prenatal genetic testing for Sanfilippo syndrome is controversial because it cannot predict the severity of the disorder. In addition, prenatal genetic testing carries serious risks, including miscarriage. Therefore, patients should discuss the potential health benefits and risks associated with these procedures with a healthcare professional or genetic counselor before making any medical decisions.
Nerve conduction study: A nerve conduction study is used to measure how quickly nerves are able to send electrical signals. To perform this test, metal electrodes are attached to the skin. One electrode is placed over a nerve and another is placed over the muscle controlled by that nerve. Clinicians can deliver a mild shock to the nerve, and measure the amount of time it takes the muscle to respond to the impulse. If the response times are slow, it may indicate a nervous system disorder.
Physical exam: A physical exam may show signs of liver and spleen swelling caused by the accumulation of heparan sulfate. There may be evidence of seizures, swallowing difficulties, and mental disabilities. Individuals with Sanfilippo syndrome are shorter than average when fully grown. Other features may include an enlarged head, full lips, and heavy eyebrows that meet in the middle of the face above the nose.
Urine test: Because people with Sanfilippo syndrome cannot break down heparan sulfate, it builds up in cells and is excreted in the urine.
X-rays: X-rays of the bones may be taken because Sanfilippo syndrome patients generally have a lower than normal bone density.

Complications

General: Complications associated with Sanfilippo syndrome all result from the gradual breakdown of the nervous system.
Impaired movement: Patients with Sanfilippo syndrome have difficulty walking due to impaired function of the nerves that control leg muscles. They often experience a loss of balance and coordination. The ability to move the arms or hands is usually also impaired, and it is common for patients to exhibit muscle spasms and loss of feeling in the hands and feet.
Nerve degeneration: Patients with Sanfilippo syndrome experience a progressive degeneration of nerve tissue. The nerve cells lose their myelin sheath, which is a covering that helps nerve cells conduct impulses. This loss causes the nerves to be unable to control muscles throughout the body, and the muscles eventually begin to waste away, or atrophy, due to lack of use.
Speech and swallowing problems: Some patients may begin to have difficulty speaking and may exhibit slurring or slowness of speech, caused by loss of muscle function around the mouth and in the tongue. For the same reason, swallowing may be difficult, which may cause choking and aspiration of food and liquid.
Other: Other complications observed in individuals with Sanfilippo syndrome include blindness, heart disease, arthritis, and skin blistering.

Treatment

General: There is currently no known cure for Sanfilippo syndrome. Treatment instead focuses on the management of symptoms and the prevention of complications. Most of the symptoms are caused by neurological degeneration, which cannot be reversed.
Assisted mobility devices: Most patients with Sanfilippo syndrome lose the ability to walk. A cane, leg braces, walker, or wheelchair may be required if walking becomes painful or difficult as a result of bone, tendon, ligament, or muscle problems.
Behavioral therapy: Behavioral therapy may benefit Sanfilippo syndrome patients who have behavioral problems. Several different types of behavioral therapy are available to improve communication and social skills, and to improve learning abilities and adaptive behaviors. The specific type of behavioral therapy used depends on the person's individual needs because people experience a wide range of symptoms that require specific treatment.
Diet: Dietary management is important for Sanfilippo syndrome patients with swallowing difficulties in order to promote physical development and keep the potential for mobility high. When the body is deprived of calories and protein, it begins to feed on its own muscles for nourishment. For this reason, maintaining adequate nutrition is very important. A speech pathologist may be able to identify whether certain foods may be particularly hazardous to a patient. To prevent choking and aspiration, solid food may be pureed and liquids may be thickened for individuals with Sanfilippo syndrome.
Occupational therapy: Patients with intellectual disabilities (formerly called mental retardation) may benefit from occupational therapy. During therapy sessions, a therapist may help the child learn to perform activities of daily living, such as feeding, dressing, and communicating with others. Some patients work with therapists who specialize in disorders accompanied by intellectual and physical disabilities. Parents and caregivers can ask their child's pediatrician to recommend a therapist.
Physical therapy: Patients with Sanfilippo syndrome may benefit from seeing a physical therapist. A physical therapist can help patients maintain muscle tone and keep muscles strong and flexible by performing different exercises.
Speech-language therapy: Some patients with Sanfilippo syndrome may benefit from speech-language therapy if they have intellectual disabilities or if they develop communication skills more slowly than normal children. Qualified speech-language professionals (SLPs) work with patients one-on-one, in small groups, or in classrooms to help patients improve speech, language, and communication skills. Programs are tailored to patients' individual needs. Speech pathologists use a variety of exercises to improve the patient's communication skills. Exercises typically start off simple and become more complex as therapy continues. For instance, the therapist may ask the patient to name objects, tell stories, or explain the purpose of an object.
Future treatments: Mutated gene carrier detection, the development of replacement enzymes, and the possibility of gene therapy are all promising future treatments. Various experimental methods have been used to try to replace the missing enzymes, but so far none have shown any significant long-term benefit. Bone-marrow and cord-blood transplantation have been considered successful in some cases, but have shown disappointing results overall. Relatively few individuals qualify for such high-risk procedures.

Integrative therapies

Note: Currently, there is a lack of scientific data on the use of integrative therapies for the treatment or prevention of Sanfilippo syndrome. The integrative therapies listed below have been studied for related conditions, such as arthritis. These therapies should be used only under the supervision of a qualified healthcare provider, and should not be used in replacement of other proven therapies or preventive measures.
Good scientific evidence:
Borage seed oil: Early evidence suggests that gamma linolenic acid (GLA) has anti-inflammatory effects that may be of benefit in rheumatoid arthritis. Additional research is needed to determine the optimal dose and administration. Avoid if allergic or hypersensitive to borage, its constituents, or members of the Boraginaceae family. Use cautiously in patients with bleeding disorders or taking warfarin or other anticoagulant or antiplatelet (blood thinning) agents. Use cautiously in patients with epilepsy or taking anticonvulsants. Avoid in patients with compromised immune systems or similar immunological conditions. Avoid in pregnant patients as borage oil may have the teratogenic and labor-inducing effects of prostaglandin E agonists, such as borage oil's GLA. Avoid if breastfeeding.
Omega-3 fatty acids: Multiple studies report improvements in morning stiffness and joint tenderness with the regular intake of fish oil supplements for up to three months. Additive benefits have been reported with nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, and other anti-inflammatory medications. Better quality research is necessary before a strong favorable recommendation can be made. Effects beyond three months of treatment have not been well evaluated.
Avoid if allergic or hypersensitive to fish, omega-3 fatty acid products that come from fish; nuts, linolenic acid, or omega-3 fatty acid products that come from nuts. Avoid during active bleeding. Use cautiously with bleeding disorders, diabetes, low blood pressure, or if taking drugs, herbs, or supplements that treat any such conditions. Use cautiously before surgery. The Environmental Protection Agency (EPA) recommends that fish intake be limited in pregnant or nursing women to a single six-ounce meal per week and in young children to less than two ounces per week. For farm-raised, imported, or marine fish, the U.S. Food and Drug Administration (FDA) recommends that pregnant or nursing women and young children avoid eating types with higher levels of methylmercury. The FDA further recommends that these individuals consume less than 12 ounces per week of other fish types. Women who might become pregnant should eat seven ounces or less per week of fish with higher levels of methylmercury or up to 14 ounces of fish with about 0.5 parts per million of methylmercury per week.
Psychotherapy: Psychotherapy is an interactive process between a person and a qualified mental health professional. The patient will explore thoughts, feelings, and behaviors to help with problem solving. Although group therapy may somewhat decrease pain in people with rheumatoid arthritis and depression, individual therapy coupled with anti-depressants may be more effective. Psychotherapy cannot always fix mental or emotional conditions. Psychiatric drugs are sometimes needed. In some cases, symptoms may get worse if the proper medication is not taken. Not all therapists are qualified to work with all problems. Use cautiously with serious mental illness or some medical conditions because some forms of psychotherapy may provoke strong emotional feelings and expression.
Unclear or conflicting scientific evidence:
Acupuncture: Acupuncture is commonly used throughout the world. According to Chinese medicine theory, the human body contains a network of energy pathways through which vital energy, called "chi," circulates. These pathways contain specific "points" that function like gates, allowing chi to flow through the body. Needles are inserted into these points to regulate the flow of chi. Some studies of weak design have reported that acupuncture may relieve pain associated with rheumatoid arthritis (RA). However, a well-designed trial was unable to confirm this. More evidence is needed to clarify if or when acupuncture is beneficial in RA.
Needles must be sterile in order to avoid disease transmission. Avoid with valvular heart disease, infections, bleeding disorders, medical conditions of unknown origin, or neurological disorders. Avoid on areas that have received radiation therapy. Avoid during pregnancy. Avoid if taking drugs that increase the risk of bleeding (anticoagulant, or blood thinning, medications). Use cautiously with pulmonary disease, such as asthma or emphysema. Use cautiously in medically compromised patients, diabetics, or the elderly. Use cautiously with a history of seizures. Avoid electroacupuncture with arrhythmia (irregular heartbeat) or in patients with pacemakers.
Astaxanthin: Astaxanthin is found in microalgae, yeast, salmon, trout, krill, shrimp, crayfish, crustaceans, and the feathers of some birds. Astaxanthin has been suggested as a possible treatment for rheumatoid arthritis. However, further research is warranted. Avoid if allergic or hypersensitive to astaxanthin or related carotenoids, including canthaxanthin or astaxanthin from algal sources. Use cautiously if taking 5-alpha-reductase inhibitors, hypertensive agents, asthma medications, drugs that are broken down by the liver, menopause agents, birth control pills, or Helicobacter pylori agents. Use cautiously with high blood pressure, parathyroid disorders, or osteoporosis. Avoid with hormone-sensitive conditions, immune disorders, or if taking immunosuppressive therapies. Avoid with previous experience of visual changes while taking astaxanthin and with low eosinophil levels. Avoid if pregnant or breastfeeding.
Ayurveda: Ayurveda is a form of natural medicine that originated in India more than 5,000 years ago. Ayurveda is an integrated system of techniques that uses diet, herbs, exercise, meditation, yoga, and massage or bodywork to achieve optimal health on all levels (physical, psychological, and spiritual). There is some evidence that a traditional Ayurvedic herbal formula, RA-1, may reduce joint swelling but not other symptoms in rheumatoid arthritis. RA-1 contains Withania somnifera (ashwagandha), Boswellia serrata (guggul), Zingiberis officinale (ginger), and Curcuma longa (turmeric). A resin extracted from Boswellia serrata (H15, indish incense) is regarded in Ayurvedic medicine as having anti-inflammatory properties. However, evidence from one study showed no benefit in patients with rheumatoid arthritis. More studies are needed to determine efficacy of these treatments in rheumatoid arthritis.
Ayurvedic herbs should be used cautiously because they are potent and some constituents can be potentially toxic if taken in large amounts or for a long time. Some herbs imported from India have been reported to contain high levels of toxic metals. Ayurvedic herbs may interact with other herbs, foods, or drugs; consult with a qualified healthcare professional before taking. Avoid Ayurveda with traumatic injuries, acute pain, advanced disease stages, or medical conditions that require surgery.
Beta-sitosterol: Beta-sitosterol is found in plant-based foods, such as fruits, vegetables, soybeans, breads, peanuts, and peanut products. It is also found in bourbon and oils, such as olive, flaxseed, and tuna. Beta-sitosterol has been shown to reduce inflammation and it has therefore been suggested as a possible treatment for rheumatoid arthritis. Further research is needed to confirm these claims. Avoid if allergic or hypersensitive to beta-sitosterol, beta-sitosterol glucoside, or pine. Use cautiously with asthma or breathing disorders, diabetes, primary biliary cirrhosis (destruction of the small bile duct in the liver), ileostomy, neurodegenerative disorders, such as Parkinson's or Alzheimer's disease, bulging of the colon, short-bowel syndrome, celiac disease, or sitosterolemia. Use cautiously with a history of gallstones. Avoid if pregnant or breastfeeding.
Black cohosh: Black cohosh is a popular alternative medicine for menopausal symptoms, such as hot flashes, migraine headache, mood changes, sleep changes, sweating, fast heartbeat, and vaginal dryness. Although it has been suggested that black cohosh may help relieve joint pain associated with rheumatoid arthritis and osteoarthritis, further research is needed. Use cautiously if allergic to members of the Ranunculaceaefamily, such as buttercup or crowfoot. Avoid with hormonal conditions (e.g., breast, ovarian, and uterine cancer or endometriosis). Avoid if allergic to aspirin products, nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen), or blood thinners, such as warfarin. Avoid with a history of blood clots, stroke, seizures, or liver disease. Stop use two weeks before and immediately after surgery or dental or diagnostic procedures with a risk of bleeding.
Black currant: The black currant shrub grows naturally in Europe and parts of Asia. Traditionally, black currant fruit has been cultivated mainly for dietary and confectionary purposes. Black currant may help reduce inflammation and morning stiffness associated with arthritis. However, additional research is needed before a firm conclusion can be drawn. Avoid if allergic or hypersensitive to black currant, its constituents, or plants in the Saxifragaceae family. Avoid with bleeding disorders or if taking blood thinners, unless otherwise directed by a qualified healthcare provider. Use cautiously with venous disorders or gastrointestinal disorders. Use cautiously if taking antidepressants or vitamin C supplements. Avoid if pregnant or breastfeeding.
Boswellia: Boswellia (Boswellia serrata)is an herb that has been shown to have anti-inflammatory properties. Because of this, boswellia has been suggested as a potential treatment for rheumatoid arthritis (RA) and osteoarthritis. However, data are conflicting and sometimes combination products have been used. There is currently insufficient evidence to recommend for or against the use of boswellia for arthritis. Avoid if allergic or hypersensitive to boswellia. Avoid with a history of stomach ulcers or stomach acid reflux disease. Avoid if pregnant or breastfeeding.
Bromelain: Bromelain is an herb that contains a digestive enzyme from the stem and the fruit of the pineapple plant. When taken with meals, bromelain may aid in the digestion of proteins. When taken on an empty stomach, it acts as an anti-inflammatory agent. In one study of the combination product ERC (enzyme-rutosid combination), results showed that ERC may be an effective and safe alternative to prescription anti-inflammatory drugs (NSAIDs), such as diclofenac, in the treatment of painful episodes of osteoarthritis of the knee. Further well-designed clinical trials of bromelain alone are needed to confirm these results. Bromelain has also been suggested as a possible treatment for rheumatoid arthritis. Further research is needed before a firm recommendation can be made.
Avoid if allergic to bromelain, pineapple, honeybee, venom, latex, birch pollen, carrots, celery, fennel, cypress pollen, grass pollen, papain, rye flour, wheat flour, or other members of the Bromeliaceaefamily. Use cautiously with a history of bleeding disorders, stomach ulcers, heart disease, or liver or kidney disease. Use cautiously before dental or surgical procedures or while driving or operating machinery. Avoid if pregnant or breastfeeding.
Cat's claw: Cat's claw is widely used in the United States and Europe and is one of the top-selling herbal remedies despite a lack of high-quality human evidence that it is effective. In Germany and Austria, cat's claw is available only by prescription. Several laboratory and animal studies suggest that cat's claw may reduce inflammation; this has led to research of cat's claw for inflammatory conditions, such as arthritis. Early research also suggests that cat's claw may reduce pain from knee osteoarthritis. Large, high-quality human studies are needed to compare the effects of cat's claw alone with those of placebo before a conclusion can be drawn.
Avoid if allergic to cat's claw, Uncaria plants, or plants in the Rubiaceae family, such as gardenia, coffee, or quinine. Avoid with a history of conditions affecting the immune system, such as AIDS, HIV infection, some types of cancer, multiple sclerosis, tuberculosis, or lupus. Use cautiously with bleeding disorders or with a history of stroke. Use cautiously if taking drugs that may increase the risk of bleeding. Stop use two weeks before and immediately after surgery or dental or diagnostic procedures with a risk of bleeding. Avoid if pregnant or breastfeeding. Cat's claw may be contaminated with other Uncaria species. Reports exist of the potentially toxic Texas-grown plant Acacia gregii being substituted for cat's claw.
Chlorophyll: Chlorophyll is responsible for the green pigment in plants. It can be obtained from green leafy vegetables (e.g.,broccoli, Brussels sprouts, cabbage, lettuce, and spinach), algae (Chlorella and Spirulina), wheat grass, and numerous herbs (alfalfa, damiana, nettle, and parsley). It has been suggested that diets high in chlorophyll modify intestinal flora, resulting in improved management of immune disorders, including rheumatoid arthritis. More evidence is needed in this area. Avoid if allergic or hypersensitive to chlorophyll or any of its metabolites. Use cautiously with photosensitivity, compromised liver function, diabetes, or gastrointestinal conditions or obstructions. Use cautiously if taking immunosuppressant agents or anti-diabetes agents. Avoid if pregnant or breastfeeding.
Copper: Copper is a mineral that occurs naturally in many foods, including vegetables, legumes, nuts, grains, fruits, shellfish, avocado, beef, and animal organs such as liver and kidney. The use of copper bracelets in the treatment of arthritis has a long tradition of use, with many anecdotal reports of effectiveness. There are research reports suggesting that copper salicylate may reduce arthritis symptoms more effectively than either copper or aspirin alone. Further study is needed before a recommendation can be made.
Avoid if allergic/hypersensitive to copper. Avoid the use of copper supplements during the early phase of recovery from diarrhea. Avoid with hypercupremia, an abnormally high concentration of copper in the blood, which occasionally occurs in disease states, including cutaneous leishmaniasis, sickle-cell disease, unipolar depression, breast cancer, epilepsy, measles, Down's syndrome, or controlled fibrocalculous pancreatic diabetes (a unique form of secondary diabetes mellitus). Avoid with genetic disorders affecting copper metabolism, such as Wilson's disease, Indian childhood cirrhosis, or idiopathic copper toxicosis. Avoid with HIV/AIDS. Use cautiously with water-containing copper concentrations greater than six milligrams per liter. Use cautiously with anemia, arthralgias (joint pains), or myalgias (muscle pains). Use cautiously if taking oral contraceptives. Use cautiously if at risk for selenium deficiency. The Recommended Dietary Allowance (RDA) is 1,000 micrograms for pregnant women. The RDA for nursing women is 1,300 micrograms.
DHEA: DHEA (dehydroepiandrosterone) is a hormone produced by the adrenal glands. Preliminary evidence from a case series suggests that DHEA likely offers no benefit to individuals with rheumatoid arthritis. Well-designed human studies are needed before firm conclusions can be drawn. Avoid if allergic to DHEA. Avoid with a history of seizures. Use cautiously with adrenal or thyroid disorders. Use cautiously if taking anticoagulants or drugs, herbs, or supplements that treat diabetes, heart disease, seizure, or stroke. Stop use two weeks before and immediately after surgery or dental or diagnostic procedures with a risk of bleeding. Avoid if pregnant or breastfeeding.
DMSO (dimethyl sulfoxide): DMSO (dimethyl sulfoxide) naturally occurs in vegetables, fruits, grains, and animal products. DMSO is available for both nonmedicinal and medicinal uses. Applying DMSO to the skin may help treat symptoms of rheumatoid arthritis. More research is needed before a conclusion can be drawn. Avoid if allergic or hypersensitive to DMSO. Use cautiously with urinary tract cancer, liver disorders, or kidney dysfunction. Avoid if pregnant or breastfeeding.
Dong quai: Dong quai (Angelica sinensis), also known as Chinese angelica, has been used for thousands of years in traditional Chinese, Korean, and Japanese medicine. Dong quai is traditionally used to treat arthritis. However, there is insufficient reliable human evidence to recommend the use of dong quai alone or in combination with other herbs for osteoarthritis or rheumatoid arthritis.
Although dong quai is recognized as a safe food additive in the United States and Europe, its safety in medicinal doses is not known. There are no reliable long-term studies of side effects available. Avoid if allergic or hypersensitive to Angelica radix or members of the Apiaceae (Umbelliferae) family (such as anise, caraway, carrot, celery, dill, and parsley). Avoid prolonged exposure to sunlight or ultraviolet light. Use cautiously with bleeding disorders or if taking drugs that may increase the risk of bleeding. Use cautiously with diabetes, glucose intolerance, or hormone sensitive conditions, such as breast, uterine, or ovarian cancer. Do not use before dental or surgical procedures with a risk of bleeding. Avoid if pregnant or breastfeeding.
Evening primrose oil: Evening primrose oil contains an omega-6 essential fatty acid called gamma-linolenic acid (GLA), which is believed to be its active ingredient. Benefits of evening primrose oil in the treatment of arthritis have not been clearly shown. More information is needed before a recommendation can be made. Avoid if allergic to plants in the Onagraceae family (e.g., willow's herb and enchanter's nightshade) or gamma-linolenic acid. Avoid with seizure disorders. Use cautiously if taking medications to treat mental illness. Stop use two weeks before surgery with general anesthesia. Avoid if pregnant or breastfeeding.
Feverfew: Feverfew (Tanacetum parthenium) is an herb native to Asia Minor. It is unclear if feverfew is an effective treatment for rheumatoid arthritis symptoms such as joint stiffness or pain. Avoid if allergic to feverfew and other plants of the Compositaefamily (such as chrysanthemums, daisies, marigolds, and ragweed). Stop use before and immediately after surgery or dental or diagnostic procedures with a risk of bleeding. Avoid with drugs that increase bleeding risk. Avoid stopping feverfew use all at once; instead, slowly take progressively smaller doses over several days. Avoid with a history of heart disease, anxiety, or bleeding disorders. Use cautiously with a history of mental illness, depression, or headaches. Avoid if pregnant or breastfeeding.
Gamma linolenic acid: Gamma linolenic acid (GLA) is a dietary fatty acid found in many plant oil extracts. A limited amount of GLA is found naturally in human breast milk, cold-water fish, and organ meats such as liver. GLA is commonly sold as a dietary supplement in capsules or as oil. Several human studies indicate significant therapeutic benefits in rheumatoid arthritis symptoms, including decreased joint tenderness, joint swelling, and pain. Some studies also suggest that GLA may be a more tolerable alternative to standard pain-reduction therapies, such as COX2 inhibitors and NSAIDs. However, there is some concern about dosage control and additional study is needed to make a recommendation in this area. Use cautiously with drugs that increase the risk of bleeding, such as anticoagulants and antiplatelet drugs. Avoid if pregnant or breastfeeding.
Ginger: The underground stems of ginger, called rhizomes, as well as the above-ground stems, have been used in Chinese, Japanese, and Indian medicine for hundreds of years. It is unclear if ginger can improve joint and muscle pain caused by rheumatoid arthritis or osteoarthritis. Avoid if allergic to ginger or other members of the Zingiberaceaefamily (such as red ginger, Alpinia purpurata, shell ginger, Alpinia zeru, green cardamom, and Balsam of Peru). Use cautiously if driving or operating machinery. Stop use two weeks before and immediately after surgery or dental or diagnostic procedures with a risk of bleeding. Avoid with a history of irregular heartbeat (arrhythmia). Use cautiously with a history of ulcers, acid reflux, heart conditions, inflammatory bowel disease, blocked intestines, or bleeding disorders. Use cautiously if pregnant or breastfeeding.
Glucosamine: Glucosamine is a natural compound found in healthy cartilage. Preliminary human research reports benefits of glucosamine in the treatment of joint pain and swelling in rheumatoid arthritis. However, this is early information and additional research is needed before a conclusion can be drawn. The treatment of rheumatoid arthritis can be complicated and a qualified healthcare provider should monitor people with this disease. Avoid if allergic or hypersensitive to shellfish or iodine. Some reports suggest a link between glucosamine and chondroitin products and asthma. Use cautiously with diabetes or with a history of bleeding disorders. Avoid if pregnant or breastfeeding.
Green tea: Green tea is made from the dried leaves of Camellia sinensis, an evergreen shrub. Research indicates that green tea may benefit arthritis by reducing inflammation and slowing cartilage breakdown. Further studies are required before a recommendation can be made. Avoid if allergic or hypersensitive to caffeine or tannins. Use cautiously with diabetes or liver disease.
Guggul: Guggul (gum guggul) is a resin produced by the mukul mirth tree. There is insufficient evidence to support the use of guggul or guggul derivatives for the management of rheumatoid arthritis. Avoid if allergic to guggul. Avoid with a history of thyroid disorders, anorexia, bulimia, or bleeding disorders. Signs of allergy to guggul may include itching and shortness of breath. Avoid if pregnant or breastfeeding.
Guided imagery: Guided imagery refers to a number of techniques, including metaphor, storytelling, fantasy, game playing, dream interpretation, drawing, visualization, active imagination, and direct suggestion, using imagery. Therapeutic guided imagery may be used to help patients relax and focus on images associated with personal issues they are confronting. Cognitive-behavioral interventions for pain may be an effective adjunct to standard pharmacologic interventions for pain in patients with juvenile rheumatoid arthritis. Further research is needed to confirm these results.
Guided imagery is usually intended to supplement medical care, not to replace it, and should not be relied on as the sole therapy for a medical problem. Contact a qualified healthcare provider if mental or physical health is unstable or fragile. Never use guided imagery techniques while driving or doing any other activity that requires full attention. Use cautiously with physical symptoms that can be brought on by stress, anxiety, or emotional upset because imagery may trigger these symptoms.
Hydrotherapy: Hydrotherapy is broadly defined as the external application of water in any form or temperature (e.g., hot, cold, steam, liquid, or ice) for healing purposes. It may include immersion in a bath or body of water, such as the ocean or a pool, use of water jets, douches, application of wet towels to the skin, or water birth. Historically, hydrotherapy has been used to treat symptoms related to rheumatoid arthritis and osteoarthritis. Multiple studies have been published, largely based on therapy given at Dead Sea spa sites in Israel. Although most studies report benefits in pain, range of motion, or muscle strength, they have been poorly designed so there is not enough reliable evidence available to draw a firm conclusion.
Avoid sudden or prolonged exposure to extreme temperatures in baths, wraps, saunas, or other forms of hydrotherapy, particularly with heart disease, lung disease, or if pregnant. Avoid with implanted medical devices, such as pacemakers, defibrillators, or hepatic (liver) infusion pumps. Vigorous use of water jets should be avoided with fractures, known blood clots, bleeding disorders, severe osteoporosis, open wounds, or during pregnancy. Use cautiously with Raynaud's disease, chilblains, acrocyanosis, erythrocyanosis, or impaired temperature sensitivity, such as neuropathy. Use cautiously if pregnant or breastfeeding. Hydrotherapy should not delay the time to diagnosis or replace treatment with better documented techniques or therapies. Hydrotherapy should not be used as the sole approach to any illness. Patients with known illness should consult their physicians before starting hydrotherapy.
Hypnosis, hypnotherapy: Hypnosis is a trance-like state in which a person becomes more aware and focused and is more open to suggestion. Hypnotherapy has been used to treat health conditions or change behaviors. Although multiple trials report diminished pain levels or requirements for pain-relieving medications after hypnotherapy, there is limited research for rheumatoid arthritis pain specifically. Other signs of rheumatoid arthritis, such as joint mobility or blood tests for rheumatoid factor, have not been adequately assessed. Use cautiously with mental illnesses such as psychosis or schizophrenia, bipolar disorder, multiple personality disorder, dissociative disorders, or seizure disorders.
Magnet therapy: Magnetic fields play an important role in Western medicine. For instance, they are used for magnetic resonance imaging (MRI), pulsed electromagnetic fields, and experimental magnetic stimulatory techniques. Several studies have evaluated the use of magnetic field therapy applied to areas of osteoarthritis or degenerative joint disease. In particular, this research has focused on knee osteoarthritis. However, most studies have been small or poorly designed or reported. Efficacy remains unclear. Notably, one promising small study published in 2004 by Wolsko et al. reported some benefits. Larger and better quality studies are needed before a recommendation can be made in this area. Initial evidence has failed to show improvements in knee pain with the use of magnet therapy. However, because of methodological weaknesses with this research, the conclusions cannot be considered definitive.
Avoid with implantable medical devices such as pacemakers, defibrillators, insulin pumps, or hepatic artery infusion pumps. Avoid with myasthenia gravis or bleeding disorders. Avoid if pregnant or breastfeeding. Magnet therapy is not advised as the sole treatment for potentially serious medical conditions and should not delay diagnosis of a condition. It should not replace treatment with better documented methods. Patients are advised to discuss magnet therapy with a qualified healthcare provider before starting treatment.
Mistletoe: Once considered a sacred herb in the Celtic tradition, mistletoe has been used for centuries to treat high blood pressure, epilepsy, exhaustion, anxiety, arthritis, vertigo (dizziness), and degenerative inflammation of the joints. According to one retrospective case study, mistletoe injections may help manage arthritis. Further research is needed before a firm conclusion can be drawn. Avoid if allergic or hypersensitive to mistletoe or any of its constituents. A life-threatening allergic reaction called anaphylaxis has been described after injections of mistletoe. Avoid with acute highly febrile (with fever) inflammatory disease, thyroid disorders, seizure disorders, or heart disease. Use cautiously with diabetes, glaucoma, or if taking cholinergics.
Moxibustion: Moxibustion is a therapeutic method used in traditional Chinese medicine (TCM), classical acupuncture, and Japanese acupuncture. During moxibustion therapy, an herb, usually mugwort, is burned above the skin or on acupuncture points to introduce heat into the point to relieve symptoms. There is preliminary evidence suggesting that patients suffering from rheumatoid arthritis may experience improved immune function as a result of acupuncture and moxibustion. However, at this time evidence is insufficient for making firm recommendations.
Use cautiously over large blood vessels and thin or weak skin. Avoid with aneurysms, any kind of "heat syndrome," heart disease, convulsions, cramps, diabetic neuropathy, extreme fatigue or anemia, fever, or inflammatory conditions. Avoid using over allergic skin conditions, ulcerated sores, or skin adhesions. Avoid areas with an inflamed organ, contraindicated acupuncture points, face, genitals, head, inflamed areas in general, and nipples. Avoid in patients who have just finished exercising or while taking a hot bath or shower. Avoid if pregnant or breastfeeding. Use cautiously with elderly people. It is not advised to bathe or shower for up to 24 hours after a moxibustion treatment.
Pantothenic acid (vitamin B5): Pantothenic acid is found in many foods including meats, liver, kidney, fish and shellfish, chicken, vegetables, legumes, yeast, eggs, and milk. It has been reported that pantothenic acid levels are lower in the blood of patients with rheumatoid arthritis compared with healthy individuals. However, it is unclear if this is a cause, effect, or a beneficial adaptive reaction. There is currently insufficient scientific evidence in this area in order to form a clear conclusion.
Pantothenic acid has also been suggested as a possible treatment for osteoarthritis. However, further research is needed to determine whether this treatment is effective. Avoid if allergic or hypersensitive to pantothenic acid or dexpanthenol. Avoid with gastrointestinal blockage. Pantothenic acid is generally considered safe in pregnant and breastfeeding women when taken at recommended doses.
Physical therapy: The goal of physical therapy is to improve mobility, restore function, reduce pain, and prevent further injuries. Several techniques, including exercises, stretches, traction, electrical stimulation, and massage are used. Physical therapy has been used to treat gonarthritis, hand, hip, and knee osteoarthritis. Manual therapy has sometimes shown better outcomes on pain, stiffness, hip function, and range of motion, although it is unclear whether sham treatment or other modalities would be comparable to physical therapy. Additional study is needed in this area.
Not all physical therapy programs are suited for everyone and patients should discuss their medical history with a qualified healthcare professional before beginning any treatment. Based on the available literature, physical therapy appears generally safe when practiced by a qualified physical therapist. Physical therapy may aggravate pre-existing conditions. Persistent pain and fractures of unknown origin have been reported. Physical therapy may increase the duration of pain or limit motion. Pain and anxiety may occur during the rehabilitation of patients with burns. Both morning stiffness and bone erosion have been reported in the literature, although the cause is unclear. Erectile dysfunction has also been reported. All therapies during pregnancy and breastfeeding should be discussed with a licensed obstetrician/gynecologist before initiation.
Podophyllum: Podophyllum rhizomes have a long history of medicinal use among native North American tribes that used the rhizome powder as a laxative or to treat infections with worms or parasites. A topical poultice made from the powder was also used to treat warts and tumorous growths on the skin. Preliminary research suggests that podophyllum may be helpful for rheumatoid arthritis. Research is limited due to possible adverse effects such as severe diarrhea associated with podophyllum taken by mouth. However, additional research is needed before a firm conclusion can be drawn.
Avoid if allergic or hypersensitive to podophyllum or to members of the Berberidaceae family. Podophyllum, when applied topically, may be absorbed through the skin and cause irritation of the stomach and intestines. Podophyllum toxicity may cause heart palpitations and blood pressure changes, muscle paralysis, difficulty walking, confusion, and convulsions. Using podophyllum and laxatives may result in dehydration and electrolyte depletion. Use cautiously with arrhythmia, Crohn's disease, cardiovascular problems, gallbladder disease or gallstones, high blood pressure, irritable bowel syndrome, liver insufficiency, muscular disorders, neurologic disorders, psychosis, and kidney insufficiency. Use cautiously if taking antimiotic agents (e.g., vincristine), antipsychotic agents, or laxatives. Avoid if pregnant or breastfeeding.
Prayer, distant healing: Prayer can be defined as a "reverent petition," the act of asking for something while aiming to connect with God or another source of worship. Prayer on behalf of the ill or dying has played a prominent role throughout history and across cultures. Initial research suggests that praying for others in the presence of patients may reduce pain, fatigue, tenderness, swelling, and weakness when used in addition to standard care. Better-quality research is necessary before a firm conclusion can be drawn.
Prayer is not recommended as the sole treatment approach for potentially serious medical conditions, and it should not delay consultation with a healthcare professional or receiving established therapies. Sometimes religious beliefs come into conflict with standard medical approaches and require an open dialog between patients and caregivers.
Probiotics: Probiotics are beneficial bacteria sometimes called friendly germs. They help maintain a healthy intestine and aid in digestion. They also help keep harmful bacteria and yeasts in the gut under control. Most probiotics come from food sources, especially cultured milk products. Probiotics can be taken as capsules, tablets, beverages, powders, yogurts, and other foods. In a small study, Lactobacillus GG was associated with improved subjective well-being and trends in reduced symptoms of rheumatoid arthritis. However, the results were not statistically significant. More studies on the effects of probiotics on rheumatoid arthritis are needed. Probiotics are generally considered safe and well tolerated. Avoid if allergic or hypersensitive to probiotics. Use cautiously if lactose intolerant.
Propolis: Bees make propolis to form their hives. Propolis is made of the buds of conifer and poplar trees and is combined with beeswax and other bee secretions. Based on anti-inflammatory action observed in laboratory research, propolis has been proposed as a possible treatment for rheumatic and other inflammatory diseases. However, there is currently not enough scientific evidence from human studies to make a clear recommendation.
Avoid if allergic or hypersensitive to propolis, black poplar (Populus nigra), poplar bud, bee stings, bee products, honey, and Balsam of Peru. Severe allergic reactions have been reported. There has been one report of kidney failure with the ingestion of propolis that improved upon discontinuing therapy and deteriorated with re-exposure. Avoid if pregnant or breastfeeding because of the high alcohol content in some propolis products.
Relaxation therapy: Relaxation techniques include behavioral therapeutic approaches that differ widely in philosophy, methodology, and practice. The primary goal is usually non-directed relaxation. In a randomized study of patients with osteoarthritis pain, Jacobson relaxation was reported to lower the level of pain perception over time. The study concluded that relaxation might be effective in reducing the amount of analgesic medication taken by participants. Further well-designed research is needed to confirm these results. Limited preliminary research reports that muscle relaxation training may improve function and well being in patients with rheumatoid arthritis. Additional research is necessary before a conclusion can be reached.
Avoid with psychiatric disorders, such as schizophrenia or psychosis. Jacobson relaxation, which involves flexing and relaxing specific muscles, should be used cautiously with illnesses such as heart disease, high blood pressure, or musculoskeletal injury. Relaxation therapy is not recommended as the sole treatment approach for potentially serious medical conditions and it should not delay diagnosis or treatment with more established techniques.
Selenium: Selenium is a mineral found in soil, water, and some foods. Selenium supplementation has been studied in rheumatoid arthritis patients with mixed results. Additional research is necessary before a clear conclusion can be drawn. Avoid if allergic or sensitive to products containing selenium. Avoid with a history of non-melanoma skin cancer. Selenium is generally regarded as safe for pregnant or breastfeeding women. However, animal research reports that large doses of selenium may lead to birth defects.
Shark cartilage: Shark cartilage is one of the most popular supplements in the United States, with more than 40 brand-name products on the market. Shark cartilage has been suggested as a possible treatment for inflammatory conditions, including rheumatoid arthritis and osteoarthritis. However, additional research is needed to determine whether this treatment is safe and effective in humans. Avoid if allergic to shark cartilage or any of its ingredients, including chondroitin sulfate and glucosamine. Use cautiously with sulfur allergy. Avoid with a history of heart attack, vascular disease, heart rhythm abnormalities (arrhythmias), or heart disease. Use cautiously with a history of liver or kidney disorders, tendency to form kidney stones, breast cancer, prostate cancer, multiple myeloma, breathing disorders such as asthma, cancers that raise calcium levels, such as breast, prostate, multiple myeloma, or squamous cell lung cancer, or diabetes. Avoid if pregnant or breastfeeding.
Stinging nettle: Stinging nettle is found in Africa, Europe, the United States, and Canada. It is a perennial plant that has been used as a medical treatment since ancient times. Nettle is widely used as a folk remedy to treat arthritic and rheumatic conditions throughout Europe and in Australia. Preliminary evidence suggests that certain constituents in the nettle plant have anti-inflammatory or immunomodulatory activity. More study is needed to confirm these findings. Nettle has historically been used in several different forms to treat pain of varying origins, including arthritis. However, there is a lack of available scientific evidence to confirm this use and additional study is needed.
Avoid if allergic or hypersensitive to nettle, the Urticaceae family, or any ingredient of nettle products. Use cautiously with diabetes, bleeding disorders, or low sodium levels in the blood. Use cautiously with diuretics and anti-inflammatory drugs. The elderly should also use nettle cautiously. Avoid if pregnant or breastfeeding.
TENS(transcutaneous electrical nerve stimulation): Transcutaneous electrical nerve stimulation (TENS) is a non-invasive technique in which a low-voltage electrical current is delivered through wires from a small power unit to electrodes located on the skin. Electrodes are temporarily attached with paste in various patterns, depending on the specific condition being treated and the treatment goals. Preliminary studies of TENS in rheumatoid arthritis report improvements in joint function and pain. However, most research is not well designed or reported and better studies are necessary before a clear conclusion can be reached. Avoid with implantable devices, such as defibrillators, pacemakers, intravenous infusion pumps, or hepatic artery infusion pumps. Use cautiously with decreased sensation (such as neuropathy) or with seizure disorders. Avoid if pregnant or breastfeeding.
Thymus extract: Thymus extracts for nutritional supplements are usually derived from young calves (and may be called bovine thymus extract). Thymus extract is commonly used to treat primary immunodeficiencies, bone marrow failure, autoimmune disorders, chronic skin diseases, recurrent viral and bacterial infections, hepatitis, allergies, chemotherapy side effects, and cancer. Further research is needed to determine whether thymus extract can effectively treat symptoms of rheumatoid arthritis.
Avoid if allergic or hypersensitive to thymus extracts. Use bovine thymus extract supplements cautiously because of the potential for exposure to the prion that causes "mad cow disease." Avoid use with an organ transplant or other forms of allografts or xenografts. Avoid with thymic tumors, myasthenia gravis (a neuromuscular disorder), or untreated hypothyroidism. Avoid if taking immunosuppressants or hormonal therapy. Avoid if pregnant or breastfeeding. Thymic extract increases human sperm motility and progression.
Turmeric: Turmeric is a perennial plant native to India and Indonesia. It is often used as a spice in cooking. Laboratory and animal studies have shown the anti-inflammatory activity of turmeric and its constituent curcumin, which may be beneficial in people with osteoarthritis or rheumatoid arthritis. Reliable human research is lacking.
Avoid if allergic or hypersensitive to turmeric (curcumin), yellow food colorings, or plants belonging to the Curcuma and Zingiberaceae (ginger) families. Use cautiously with a history of bleeding disorders, immune system deficiencies, liver disease, or gallstones. Use cautiously if taking blood thinners such as warfarin (Coumadin?). Use cautiously if pregnant or breastfeeding.
Zinc: Zinc formulations have been used since ancient Egyptian times to enhance wound healing. The majority of trials do not show significant improvements in arthritis symptoms following zinc treatment. Interpretation of some data is difficult because patients in the studies were permitted to continue taking their arthritis medication, and most studies used a small number of participants. Well-designed clinical trials are needed before a recommendation can be made. Zinc is generally considered safe when taken at the recommended dosages. Avoid zinc chloride since studies have not been done on its safety or effectiveness. While zinc appears safe during pregnancy in amounts lower than the established upper intake level, caution should be used since studies cannot rule out the possibility of harm to the fetus.
Fair negative scientific evidence:
Willowbark: Willowbark that contains salicin has been used to treat many different kinds of pain. There is good evidence that willow bark may be effective in treating chronic pain from osteoarthritis. However, willow bark extract did not show efficacy in treating rheumatoid arthritis. Additional study is needed to make a firm recommendation.
Avoid if allergic or hypersensitive to aspirin, willow bark (Salix family), or any of its constituents, including salicylates. Use cautiously with gastrointestinal problems such as ulcers, liver disorders, diabetes, gout (foot inflammation), high blood pressure, or high cholesterol. Use cautiously with a history of allergy, asthma, and leukemia. Use cautiously if taking protein-bound medications, antihyperlipidemia agents, alcohol, leukemia medications, beta-blockers, diuretics, phenytoin (Dilantin?), probenecid, spironolactone, sulfonylureas, valproic acid, or methotrexate. Use cautiously if predisposed to headaches. Use cautiously with use of tannin-containing herbs or supplements. Avoid when operating heavy machinery. Avoid in children with chickenpox and any other viral infections. Avoid with blood and kidney disorders. Avoid if taking other NSAIDs, acetazolamide, or other carbonic anhydrase inhibitors. Avoid with elevated serum cadmium levels. Avoid if pregnant or breastfeeding.
Zinc: Zinc formulations have been used since ancient Egyptian times to treat a variety of medical conditions. Early studies found that zinc supplementation did not seem to benefit patients with chronic inflammatory rheumatic disease.
Zinc is generally considered safe when taken at the recommended dosages. Avoid zinc chloride because studies have not evaluated its safety or effectiveness. While zinc appears safe during pregnancy in amounts lower than the established upper intake level, caution should be used because studies cannot rule out the possibility of harm to the fetus.

Prevention

If a person has a family history of Sanfilippo syndrome, genetic testing may be performed to determine whether mutations are present that affect any of the four genes responsible for heparan sulfate degradation. Although carriers do not have the disease, they can pass a copy of the mutated gene to their children.
Prenatal DNA testing may be performed if there is a family history of Sanfilippo syndrome. Diagnosis during pregnancy is possible using chorionic villus sampling (CVS) at about 11 weeks or amniocentesis at around 14 weeks. However, there are health risks associated with prenatal genetic testing, including miscarriage.
Before and after genetic testing, individuals should meet with a genetic counselor, who can help them understand the risks of having a child with Sanfilippo syndrome. A genetic counselor can also explain the different types of genetic tests, including their potential risks and benefits. These counselors can help patients understand and interpret the test results.
Patients diagnosed with Sanfilippo syndrome should undergo regular checkups with their doctors in order to reduce the risk of developing complications.

Author information

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

Aydin M, Akarsu S, Kabakus N, et al. Mucopolysaccharidosis IIIB, cerebral vasculopathy and recurrent subdural hematoma. Indian Pediatr. 2006 May;43(5):437-40.
Beesley CE, Jackson M, Young EP, et al. Molecular defects in Sanfilippo syndrome type B (mucopolysaccharidosis IIIB). J Inherit Metab Dis. 2005;28(5):759-67.
Hreb?cek M, Mr?zov? L, Seyrantepe V, et al. Mutations in TMEM76* cause mucopolysaccharidosis IIIC (Sanfilippo C syndrome). Am J Hum Genet. 2006 Nov;79(5):807-19.
Moog U, van Mierlo I, van Schrojenstein Lantman-de Valk HM, et al. Is Sanfilippo type B in your mind when you see adults with mental retardation and behavioral problems? Am J Med Genet C Semin Med Genet. 2007 Aug 15;145(3):293-301.
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Yogalingam G, Hopwood JJ. Molecular genetics of mucopolysaccharidosis type IIIA and IIIB: Diagnostic, clinical, and biological implications. Hum Mutat. 2001 Oct;18(4):264-81.

Causes

General: Sanfilippo syndrome results when the enzymes needed to break down heparan sulfate are missing or defective.
Genetic mutations: Each of the four types of Sanfilippo syndrome is caused by a mutation in a different gene responsible for encoding or providing instructions for making a specific enzyme that breaks down heparan sulfate. Mutations in the heparan sulfate sulfatase gene cause type A Sanfilippo syndrome. Mutations in the alpha-N-acetylglucosaminidase gene cause type B Sanfilippo syndrome. Mutations in the acetyl-CoA alpha-glucosaminide N-acetyltransferase gene cause type C Sanfilippo syndrome. Mutations in the N-acetylglucosamine 6-sulfatase gene cause type D Sanfilippo syndrome.
Inheritance: Sanfilippo syndrome is an inherited disorder passed down in families as an autosomal recessive trait. Individuals have two copies of most genes (one inherited from the father and one from the mother). In a recessive genetic disorder, both copies of a certain gene need to be defective for the condition to occur.
People who have only one mutated gene usually do not show symptoms of the disease, but are called "carriers" because they may pass the mutated gene to their children. If only one parent is a carrier, none of the children will have Sanfilippo syndrome, but each child has a 50% chance of inheriting one mutated gene and of being a carrier.
If both parents are carriers, then each child has a 50% chance of also being a carrier, a 25% chance of inheriting two copies of the defective gene and having the disease, and a 25% chance of not inheriting either mutated gene and not having the disease.

Risk factors

Because Sanfilippo syndrome is inherited, the only known risk factor is a family history of the disorder. Certain populations are known to have a higher incidence of Sanfilippo syndrome, such as the populations of Britain and the Cayman Islands.

Types of the disease

There are four main types of Sanfilippo syndrome, which is also called mucopolysaccharidosis type 3 (MPS III). There are four different genes that, when mutated or defective, provide incorrect instructions for making enzymes that break down heparan sulfate. These incorrect instructions result in enzymes that cannot adequately break down heparan sulfate. The gene and enzyme that are affected determine the type of Sanfilippo syndrome.
Sanfilippo type A: Type A is the most severe form of Sanfilippo syndrome. In this type of the disease, the enzyme heparan sulfate sulfatase is altered or absent.
Sanfilippo type B: In type B Sanfilippo syndrome, the enzyme alpha-N-acetylglucosaminidase is absent or deficient. Type B is generally milder than type A. On average, symptoms of type B start to appear between 40 and 60 years of age and may include heart disease, arthritis, skin blistering, swallowing problems, seizures, and behavioral problems (restlessness, screaming, and hitting). One study in the Netherlands showed that type B is the most common subtype of mucopolysaccharidosis in that country. It is believed that type B is underdiagnosed in adults with mental disabilities.
Sanfilippo type C: In type C Sanfilippo syndrome, the enzyme acetyl-CoA alpha-glucosaminide N-acetyltransferase is absent or inadequate.
Sanfilippo type D: In type D Sanfilippo syndrome, the enzyme N-acetylglucosamine 6-sulfatase is absent or deficient.