Juvenile Huntington chorea: clinical, ultrastructural, and biochemical studies.

A brain biopsy from a 20-year-old patient whose clinical course was marked by progressive dementia and chorea since age 10 years showed increased amounts of lipofuscin, abnormal mitochondria, and other organelles in cortical neurons, neurites, and astrocytes. Juvenile Huntington chorea was confirmed at autopsy. High levels of three histone-like proteins (molecular weight 10,000 to 16,000) in the microsomal fraction of purified neurons were found by SDS-polyacrylamide gel electrophoresis. Fatty acids were abnormal in white matter sphingomyelin. These ultrastructural and biochemical findings conformed to those established in adult Huntington chorea, thus strengthening the concept of a uniform pathologic process in adult and juvenile Huntington diseases in spite of some clinical and histologic differences.