PROGRESSIVE FAMILIAL LEUKODYSTROPHY OF LATE-ONSET

We report a family in which three siblings developed dementia between the ages of 40 and 70 years. Two of the siblings developed symptoms of depression, abnormal behavior, and an inability to function, progress ing to severe dementia. The third sibling had a severe dementia, the c linical details of which are not available, In the two deceased siblin gs, neuropathologic examinations demonstrated severe demyelination, ax on loss, and gliosis in cerebral white matter. Cerebellar and brainste m white matter were unaffected. Cerebral gray matter was negligibly af fected. The disorder, histopathologically classified as a pigmented or thochromatic leukodystrophy, is extremely rare. Its etiology is unknow n, but the pathology and familial occurrence imply that it represents a genetic defect in a function localized in the cerebral white matter.