A family with hereditary ataxia: HLA typing.

In a previously unreported family with olivopontocerebellar atrophy, the kindred contained over 600 individuals in five generations. Of 83 offsping of affected individuals who over over 38.8 years of age (the mean age of the onset of disease in this family), 47 had ataxia; there was autosomal dominant transmission. Clinical findings included lower bulbar palsies, hyperreflexia, ataxia, incoordination, scanning and explosive speech, and, in some, slow motor-nerve conduction velocities. There was cortical and cerebellar atrophy of pontine nuclei, inferior olives, and XII nuclei, and loss of Purkinje cells in the cerebellum. Seventy-three individuals of the III and IV generations were typed for HLA histocompatibility antigens. A maximum lod score of 1.97 was found at male recombination fraction 0.18 and female recombination fraction 0.36. When the lod score values reported in other studies were combined with the values in this family, the maximum lod score was found to be 4.681 at a recombination frequency of 0.22.