HYPOPLASIA OF THE CEREBELLAR VERMIS AND CORPUS-CALLOSUM IN THROMBOCYTOPENIA WITH ABSENT RADIUS SYNDROME ON MRI STUDIES

Thrombocytopenia with absent radius (TAR) syndrome is infrequently (7% ) associated with mental retardation. In those cases, the mental defic iency is presumed to be a consequence of intracranial hemorrhage due t o the thrombocytopenia, We report on 2 infants with TAR syndrome. One had developmental delay with evidence of cerebral dysgenesis by magnet ic resonance imaging (MRI). Such findings have not been noted in the l iterature, but may not have been investigated in most cases. The other infant with TAR syndrome, who has had normal psychomotor development, has a normal brain on MRI scan. Detailed neuroimaging studies, prefer ably MRI, should be considered in the evaluation of patients with TAR syndrome, especially when there are documented signs of developmental delay, with or without a history of intracranial hemorrhage. (C) 1994 Wiley-Liss, Inc.