Heredity in multiple system atrophy.

We investigated the family histories of 157 Japanese patients with probable or possible multiple system atrophy (MSA). A family history of neurodegenerative disorders was only detected in three MSA patients (1.9%). We evaluated these patients by careful neurological examination, neuroimaging studies, and genetic studies to exclude hereditary spinocerebellar ataxia with a similar clinical phenotype to MSA. The results indicated that one of them had a family history of MSA. Although the familial presence of neurodegenerative disorders is rare in MSA patients, the existence of such cases suggests that MSA may have a genetic background.