Ataxia-oculomotor apraxia syndrome.

Ataxia-oculomotor apraxia is a distinct entity first comprehensively described in 1988. The features include early childhood onset of ataxia and oculomotor apraxia, mimicking ataxia telangiectasia but without the extraneurologic findings of ataxia telangiectasia. We add to the clinical description of the ataxia-oculomotor apraxia syndrome by reporting eight patients, ages 2 to 15 years, from four families, suggesting autosomal recessive inheritance, with the longest follow-up over 6 years. After initial gait deterioration, all had a nonprogressive course. We have postulated that ataxia-oculomotor apraxia should be established as a separate disease from ataxia telangiectasia or its variants not only by clinical history, examination findings, and course, but primarily by the biologic markers of normal chromosome breakage and radiation sensitivity studies. We found no increased chromosome breakage in the four patients studied and intermediate sensitivity to chronic ionizing radiation of cultured skin fibrobl...