Spinocerebellar Ataxia, X-Linked 4

For a discussion of genetic heterogeneity of X-linked spinocerebellar ataxia (SCAX), see SCAX1 (302500).

Clinical Features

Farlow et al. (1987) described a large kindred in which males of 3 generations connected through females showed an apparently X-linked syndrome comprising ataxia, pyramidal tract signs and adult-onset dementia. Initial signs, manifested by 2 to 3 years of age, were delayed walking and tremor. During their teens, the patients would develop mild but progressive ataxia and pyramidal signs. Memory problems in the third decade initiated a progressive dementia, leading to death in the sixth decade. Laboratory investigations failed to disclose an abnormality. Preliminary linkage studies using RFLPs suggested that Xq26-qter and much of the short arm could be excluded as sites for the gene.