Metachromatic leukodystrophy (MLD) is one of a group of genetic disorders called the leukodystrophies. These diseases impair the growth or development of the myelin sheath, the fatty covering that acts as an insulator around nerve fibers. Myelin, which lends its color to the white matter of the brain, is a complex substance made up of at least 10 different enzymes. The leukodystrophies are caused by genetic defects in how myelin produces or metabolizes these enzymes. Each of the leukodystrophies is the result of a defect in the gene that controls one (and only one) of the enzymes. MLD is caused by a deficiency of the enzyme arylsulfatase A. MLD is one of several lipid storage diseases, which result in the toxic buildup of fatty materials (lipids) in cells in the nervous system, liver, and kidneys. There are three forms of MLD: late infantile, juvenile, and adult. Onset of the late infantile form (the most common MLD)  is typically between 12 and 20 months following birth.  Affected children have difficulty walking after the first year of life. Symptoms include muscle wasting and weakness, muscle rigidity, developmental delays, progressive loss of vision leading to blindness, convulsions, impaired swallowing, paralysis, and dementia. Children may become comatose. Most children with this form of MLD die by age 5. The juvenile form of MLD (between 3-10 years of age) usually begins with impaired school performance, mental deterioration, and dementia and then develop symptoms similar to the infantile form but with slower progression. The adult form commonly begins after age 16 as a psychiatric disorder or progressive dementia. Symptoms include impaired concentration, ataxia, seizures, dementia, and tremor.. There is no cure for MLD.  Bone marrow transplantation may delay progression of the disease in some cases. Other treatment is symptomatic and supportive. Considerable progress has been made with regard to gene therapy in an animal model of MLD. The prognosis for MLD is poor. Most children within the infantile form die by age 5. Symptoms of the juvenile form progress with death occurring 10 to 20 years following onset.  Those persons affected by the adult form typically die withing 6 to 14 years following onset of symptoms. The National Institute of Neurological Disorders and Stroke (NINDS), a part of the National Institutes of Health (NIH), conducts research on the lipid storage diseases in laboratories at the NIH and also supports additional research through grants to major medical institutions across the country.Considerable progress has been made with regard to gene therapy in an animal model of MLD. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&term=(leukodystrophy+metachromatic+OR+metachromatic+leukodystrophy)+AND+human[mh]+AND+english[la]+AND+(review[ptyp]+OR+review+literature[mh]+OR+practice+guideline[ptyp]+OR+guideline[ptyp]+OR+clinical+trials[mh]+OR+clinical+trial[ptyp]+OR+consumerj[sb])&db=PubMed&orig_db=PubMed&filters=on&pmfilter_EDatLimit=5+Years 1 http://clinicaltrials.gov/ct2/results?term= /disorders/metachromatic_leukodystrophy/pubs_metachromatic_leukodystrophy.htm /disorders/metachromatic_leukodystrophy/xml_metachromatic_leukodystrophy.xml xml_metachromatic_leukodystrophy.xml V100 The Arc of the United States

1010 Wayne Avenue

Suite 650 Silver Spring MD 20910 Info@thearc.org http://www.thearc.org 301-565-3842 800-433-5255 301-565-3843 or -5342 Works to protect and expand the opportunities available to persons with mental retardation and related developmental disabilities. V303 Myelin Project

P.O. Box 39

Pacific Palisades CA 90272 margaret.weis@myelin.org http://www.myelin.org 800-869-3546 310-459-1071 310-230-4298 Aims to accelerate research on repair of myelin, the white matter insulating the nerves, which can be destroyed by hereditary metabolic disorders, such as the leukodystrophies, and acquired disorders, such as multiple sclerosis. V91 National Organization for Rare Disorders (NORD)

P.O. Box 1968

(55 Kenosia Avenue) Danbury CT 06813-1968 orphan@rarediseases.org http://www.rarediseases.org 203-744-0100 Voice Mail 800-999-NORD (6673) 203-798-2291 Federation of voluntary health organizations dedicated to helping people with rare "orphan" diseases and assisting the organizations that serve them. Committed to the identification, treatment, and cure of rare disorders through programs of education, advocacy, research, and service. V223 National Tay-Sachs and Allied Diseases Association

2001 Beacon Street

Suite 204 Boston MA 02135 info@ntsad.org http://www.ntsad.org 800-90-NTSAD (906-8723) 617-277-0134 The mission of the National Tay-Sachs & Allied Diseases Association is to lead the fight to treat and cure Tay-Sachs, Canavan and related genetic diseases and to support affected families and individuals in leading fuller lives. V155 United Leukodystrophy Foundation

2304 Highland Drive

Sycamore IL 60178 office@ulf.org http://www.ulf.org 815-895-3211 800-728-5483 815-895-2432 Nonprofit voluntary health organization dedicated to providing patients and their families with information; assistance in identifying sources of medical care, social services, and genetic counseling; establishing a communication network among families; increasing public awareness, and acting as an information source for health care providers. Promotes supports research into causes, treatments, and prevention of the leukodystrophies. V879 MLD Foundation

21345 Miles Drive

West Linn OR 97068 info@MLDFoundation.org http://www.MLDfoundation.org 800-617-8387 503-656-4808