Walsh & Hoyt: Degenerations of White Matter

Pelizaeus-Merzbacher disease. This rare and slowly progressive disease of white matter is caused by a defect in the production of the proteolipid protein, the major myelin protein of the CNS. It has onset in infancy. It is X-linked with the gene for the classic form at Xq22. The brains of affected patients demonstrate lack of myelination. Other findings include the loss of periodicity of the myelin, loss of mature oligodendrocytes, and astrocytosis. Some of the oligodendrocytes contain spherical lamellated cytoplasmic inclusions and myelin balls at their periphery. Prenatal diagnosis and carrier detection are possible in some cases. Krabbe disease (globoid cell leukodystrophy).