Two new cases of thrombocytopenia absent radius (TAR) syndrome: clinical, genetic and nosologic features.

Two unrelated children affected by TAR syndrome, autosomic recessive disease with congenital thrombocytopenia and bilateral radial aplasia, are described. In the first case a mild thrombocytopenia has been compatible with a fairly normal life until the second year of age. The other child shows radial aplasia associated with other anomalies of the upper limbs, severe thrombocytopenia and leukemoid reaction. The relationship among TAR syndrome, Fanconi's anemia and Roberts' syndrome are briefly discussed.