A 58-year-old male with spinocerebellar degeneration in association with choreiform movement is described. He possessed neurological, biochemical, immunological, as well as cytogenetic disorders predisposing to cancer to patients with ataxia telangiectasia (AT). Cytogenetic abnormalities included four abnormal clones: trisomy 14;t(13;14);t(7;14)(q32;q12); and t(7;14)(p13;q12), in addition to breaks, rings, and acentric chromosomes. The absence of telangiectasia, the late onset of neurological symptoms, and the prolonged survival in this case may separate it from the classic AT. Although the syndrome may be recognized as a new chromosome instability syndrome, multiple allelism may play a role in the expression of a milder form of AT.