GENETIC-HETEROGENEITY OF FAMILIAL HEMIPLEGIC MIGRAINE

Familial hemiplegic migraine (FHM) is a distinctive form of migraine w ith an autosomal dominant mode of inheritance. The migraine-like attac ks are associated with transient hemiparesis. A locus for FHM has rece ntly been assigned to chromosome 19 by linkage mapping. In the present study, five unrelated pedigrees with multiple members suffering from hemiplegic migraine were investigated. In two of the pedigrees additio nal symptoms, cerebellar ataxia and benign neonatal convulsions, respe ctively, were observed in affected members. Three pedigrees showed lin kage to loci D19S391, D19S221, and D19S226 at chromosome 19p13. Haplot yping suggested a location of a FHM gene between D19S391 and D19S221. In the two remaining families, evidence against linkage was found. The se results confirm the localization of a gene for familial hemiplegic migraine to the short arm of chromosome 19, but locus heterogeneity no t corresponding to the observed clinical heterogeneity is likely to ex ist. (C) 1994 Academic Press, Inc.