Metachromatic leukodystrophy (MLD) is the most common form of a family of genetic diseases known as the leukodystrophies, diseases which affect the growth and/or development of myelin, the fatty covering which acts as an insulator around nerve fibres throughout the central and peripherial nervous systems . The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... Leukodystrophy refers to progressive degeneration of the white matter of the brain due to imperfect growth or development of the myelin sheath, the fatty covering that acts as an insulator around nerve fiber. ... In neuroscience, myelin is an electrically insulating fatty layer that surrounds the axons of many neurons. ... Nerves (yellow)    Nerves redirects here. ... Look up Central in Wiktionary, the free dictionary Central is the name of several places: Central — a region of Scotland Central — another name for the Blue Nile state of Sudan Central — an area in Hong Kong, part of Central and Western District Central City — a city in Nebraska Central — a... The nervous system of an animal coordinates the activity of the muscles, monitors the organs, constructs and processes input from the senses, and initiates actions. ...

Causes

MLD is directly caused by a deficiency of the enzyme arylsulfatase A. Without this, suflitides build up in many tissues of the body, eventually destroying the myelin of the nervous system.

Symptoms and Forms

Like many other genetic disorders that affect lipid metabolism, there are several forms of MLD, which are late infantile, juvenile, and adult.

In the late infantile form, which is the most common form MLD, affected children being having 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. Untreated, most children with this form of MLD die by age 5.

Children with the juvenile form of MLD (onset between 3-10 years of age) usually begin with impaired school performance, mental deterioration, and dementia and then develop symptoms similar to the late infantile form but with slower progression. Age of death is variable, but normally within 10 to 15 years of symptom onset.

The adult form commonly begins after age 16 as a psychiatric disorder or progressive dementia. Adult-onset MLD progresses more slowly than the late infantile and juvenile forms, with a protracted course of a decade or more.

Treatment

There is no cure for MLD, nor a standard form of treatment. Children with advanced juvenile or adult onset, and late infantile patients displaying symptoms have treatment limited to pain and symptom management. Presymptomatic late infantile MLD patients, as well as those with juvenile or adult MLD that are either presymptomatic or displaying mild to moderate symptoms, have the option of bone marrow transplantation, which may slow down the progression of the disease, or stop its progression.

Treatment options for the future that are currently being investigated include gene therapy and enzyme replacement therapy.

Links and Sources

Large portions of this article are courtesy of the public domain text available at the National Institute for Neurological Disorders and Stroke. Located at: http://ninds.nih.gov/disorders/metachromatic_leukodystrophy/metachromatic_leukodystrophy.htm Further information regarding MLD, and current research projects, can be found at The Stennis Foundation, located at http://www.stennisfoundation.org.