Leukodystrophy

Classification and external resources
T2 weighted axial scan at the level of the caudate heads demonstrates marked loss of posterior white matter, with reduced volume and increased signal intensity. The anterior white matter is spared. Features are consistent with X-linked Adrenoleukodystrophy.
ICD-10	E75.2
ICD-9	330.0
DiseasesDB	32504

Leukodystrophy refers to a group of disorders characterized by dysfunction of the white matter of the brain. The leukodystrophies are caused by imperfect growth or development of the myelin sheath, the fatty covering that acts as an insulator around nerve fibers. Myelin, from which the white matter of the brain takes its colour, is a complex substance made up of at least ten different chemicals. Each of the leukodystrophies is the result of a defect in the gene that controls the production or metabolism of one (and only one) of the component molecules of myelin.

The word leukodystrophy comes from the Greek roots leuko, white, dys, lack of, and troph, growth. Thus leukodystrophy describes a set of diseases that affect the growth or maintenance of the white matter.

Types

Specific leukodystrophies include (ICD-10 codes are provided where available):

• (E71.3) adrenoleukodystrophy
• (E71.3) adrenomyeloneuropathy
• (E75.2) metachromatic leukodystrophy
• Hereditary CNS demyelinating disease
  • (E75.2) Krabbe disease
  • (E75.2) Pelizaeus-Merzbacher disease
  • Canavan disease
  • Leukoencephalopathy with vanishing white matter, also known as childhood ataxia with central nervous system hypomyelination (CACH) or vanishing white matter disease.
  • Alexander disease
• (G60.1) Refsum disease
• cerebrotendineous xanthomatosis

Cause

Leukodystrophies are mostly inherited disorders. They may be inherited in a recessive, dominant, or X-linked manner, depending on the type of leukodystrophy. The individual articles on each leukodystrophy will describe the particular pattern of inheritance for that disease. There is also a fact sheet describing the different genetic inheritance patterns available from the United Leukodystrophy Foundation.

There are some leukodystrophies that do not appear to be inherited, but rather arise spontaneously. They are still caused by a mutation in a particular gene, but it means that the mutation was not inherited.

Symptoms

The most common symptom of a leukodystrophy disease is a gradual decline in an infant or child who previously appeared well. Progressive loss may appear in body tone, movements, gait, speech, ability to eat, vision, hearing and behaviour. There is often a slowdown in mental and physical development. Symptoms vary according to the specific type of leukodystrophy, and may be difficult to recognise in the early stages of the disease.

Current research

One source of active (as of 2006) research is The Myelin Project. In addition, many research groups are studying the cellular processes of myelination, which may provide insights into leukodystrophy.

Possible cure

In February 2013, New York scientists find a treatment that proves itself successful in mice. Further experiments in humans will follow.^{[citation needed]}

Public awareness

Jill Kelly and her husband, NFL quarterback Jim Kelly, of the US founded Hunter's Hope Foundation after their son Hunter died of Krabbe leukodystrophy.

Matthew and Michael Clark of Hull, UK, have terminal leukodystrophy. They are the subjects of the Channel 4 documentary The Curious Case of the Clark Brothers.

See also

• Leukoencephalopathy

External links

• "Hematopoietic Stem-Cell Transplantation in Globoid-Cell Leukodystrophy " WIlliam Krivit MD Phd et al, N Engl J Med 1998; 338:1119-1127April 16, 1998 [1]
• This article incorporates public domain text from the National Institute of Neurological Disorders and Stroke.
• Leukodystrophy at the Open Directory Project
• Leukodystrophy Alliance
• MLD Foundation - metachromatic leukodsytrophy
• UK Documentary Concerning the Clarke Brothers