AN AUTOSOMAL RECESSIVE DISORDER WITH POSTERIOR COLUMN ATAXIA AND RETINITIS-PIGMENTOSA

We report an autosomal recessive form of ataxia that is not allelic to Friedreich's disease in six individuals from a large kindred with fam ily origins traced to a common founder of German-Swiss descent. The di sorder begins during early childhood with a concentric contraction of the visual fields and proprioceptive loss. Eventually blindness, a sev ere sensory ataxia, achalasia, scoliosis, and inanition develop by the third decade. Inversion recovery MRIs of the spinal cord in affected individuals demonstrate a hyperintense signal in the posterior columns . Finding the gene responsible for this disorder may aid in our unders tanding of the mechanisms that cause sensory neuronal degeneration.