Leukodystrophy

A disorder of the white matter of the brain, the part of the brain that contains myelinated nerve fibers. The white matter is white because it is the color of myelin, the insulation covering the nerve fibers. (The white matter is as opposed to the gray matter, the cortex of the brain which contains the nerve cell bodies). The white matter is involved in the conduction of nerve impulses in the brain.

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Term for a group of white matter diseases, some familial, characterized by progressive cerebral deterioration usually in early life, and pathologically by primary absence or degeneration of the myelin of the central and peripheral nervous systems with glial reaction; probably related to a defect in lipid metabolism; most leukodystrophies are autosomal recessive, several X-linked recessive, and a few autosomal dominant. SEE ALSO: Canavan disease. SYN: leukodystrophia cerebri progressiva, leukodystrophia, sclerosis of white matter. [leuko- + G. dys, bad, + trophe, nourishment]

- adrenal l. sudanophilic l. with bronzing of skin and adrenal atrophy. A metabolic disorder of young males, characterized by widespread myelin degeneration and associated adrenal insufficiency. The myelin degeneration is massive in various portions of the brain and sometimes the spinal cord, with the accumulation of degradation products of myelin in macrophages: sudanophilic demyelination; atrophy is present in the adrenal glands and testes, and markedly increased amounts of very long-chain fatty acid are present in both the brain and adrenal glands. Symptoms include bronzing of the skin, dysarthria, cortical blindness, bilateral hemiplegia, pseudobulbar paralysis, and progressive dementia. Probably sex-linked recessive inheritance.

- globoid cell l. [MIM*245200] a metabolic disorder of infancy or early childhood characterized by spasticity, seizures, and rapidly progressive cerebral degeneration, massive loss of myelin, severe astrocytic gliosis, and infiltration of the white matter with characteristic multinucleate globoid cells; metabolically there is gross deficiency of lysosomal cerebrosidase (galactosylceramide β-galactosidase); autosomal recessive inheritance, caused by mutation in the gene encoding glycosylceramidase (GALC) on 14q. SYN: diffuse infantile familial sclerosis, galactosylceramide lipoidosis, Krabbe disease.

- metachromatic l. [MIM*250100] a metabolic disorder, with onset usually in the second year of life and death often before 5 years, with loss of myelin and accumulation of metachromatic lipids (galactosyl sulfatidates) in the white matter of the central and peripheral nervous systems leading to motor symptoms, paralysis, convulsions, and progressive cerebral deterioration; . Autosomal recessive inheritance [MIM*249900 and MIM*250100], caused by mutation in either the arylsulfatase A gene (ARSA) on 22q or the prosaposin gene (PSAP) on 10q. There is a dominant form occurring in adults [MIM*156310]. SYN: arylsulfatase A deficiency, sulfatide lipidosis.

- l. with diffuse Rosenthal fiber formation a metabolic disorder whose onset can be in infancy, adolescence, or adulthood; characterized pathologically by widespread cerebral demyelination with astrocyte and primitive oligodendroglial cell proliferation; refractile Rosenthal fiber s result from the degeneration of these proliferating cells; etiology unknown, but possibly due to a metabolic defect of astrocytes; sex-linked recessive disorder.

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leu·ko·dys·tro·phy or chiefly Brit leu·co·dys·tro·phy .lü-kō-'dis-trə-fē n, pl -phies any of several inherited diseases (as adrenoleukodystrophy) characterized by progressive degeneration of myelin in the brain, spinal cord, and peripheral nerves

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leu·ko·dys·tro·phy (loo″ko-disґtrə-fe) any of various types of neurodegeneration involving disturbance of the white matter of the brain. See also adrenoleukodystrophy and leukoencephalopathy.