INFANTILE ONSET SPINOCEREBELLAR ATAXIA REPRESENTS AN ALLELIC DISEASE DISTINCT FROM OTHER HEREDITARY ATAXIAS

Hereditary ataxias are a heterogeneous group of progressive neurodegen erative disorders characterized by symptoms and signs originating main ly in the CNS. A new representative of this disease group is infantile onset spinocerebellar ataxia, an autosomal recessively inherited synd rome so far reported only in the genetically isolated Finnish populati on. The etiology of hereditary ataxias still remains unknown, but the gene loci behind many of them have been mapped to different chromosoma l regions. We have carried out linkage analyses with markers on the re gions of the previously identified ataxia loci to determine whether th e infantile onset spinocerebellar ataxia syndrome represents the same allelic disease as any of the previously identified hereditary ataxias . Here we report that the infantile onset spinocerebellar ataxia syndr ome does not segregate with any of the markers closely linked to the o ther hereditary ataxias. Consequently, it represents a genetically dis tinct disease, the gene locus of which still has to be identified.