Thrombocytopenia and absent radii (TAR) syndrome associated with horseshoekidney

The TAR syndrome is an inherited disorder characterized by limb abnormaliti es, especially absent radii, and hypomegakaryocytic thrombocytopenia. Previ ous reports have included two infants with genitourinary abnormalities. We report a newborn with bilaterally absent radii and foreshortened ulnae, hyp oplastic humeri, a left clubfoot, a ventricular septum defect, and persiste nt thrombocytopenia. This constellation of abnormalities is consistent with the TAR syndrome. In addition, he had a horseshoe kidney with parenchyma o f normal appearance. This is the first report of horseshoe kidney in associ ation with the TAR syndrome.