Ataxia with oculomotor apraxia.

Ataxia-telangiectasia (AT) belongs to a group of recessively inherited disorders characterized by progressive ataxia and oculomotor apraxia. Included in this group are AT, ataxia-telangiectasia-like disorder (ATLD), ataxia with oculomotor apraxia type 1 (AOA 1), ataxia with oculomotor apraxia type 2 (AOA 2), and the recently described AOA3. Common to this group is the underlying cellular defect in the recognition and repair of double-strand or single-strand DNA breaks. Clinical and laboratory features allow one to distinguish between these various disorders. In this report, we describe a child with early onset progressive ataxia, oculomotor apraxia, ocular telangiectasia, and white-matter changes by magnetic resonance imaging, which appears to be yet another novel form of AOA. We designate this condition as AOA-WM to call attention to the central demyelination seen in this variety of ataxia with oculomotor apraxia.