Late onset bone marrow failure associated with proximal fusion of radius and ulna: a new syndrome.

Members of two unrelated families, one from England and the other from Portugal, presented with aplastic anaemia. Both families had clinical and laboratory features in common. The proposita presented with progressive bone marrow failure in adult life involving all three haemopoietic cell lines. In both families individuals with bone marrow failure also had proximal fusion of the radius and ulna bilaterally which segregates as an autosomal dominant trait. No cytogenetic defect was identified in myeloid or lymphoid cells, sampled from the marrow and peripheral blood. Proximal fusion of the radius and ulna is uncommon and its co-existance with late onset bone marrow failure may indicate an association. Growth failure, non-skeletal congenital malformations and cytogenetic abnormalities were absent suggesting that this syndrome is distinct from Fanconi's anaemia. The onset in adult life of generalized bone marrow failure involving all three haemopoietic cell lines associated with proximal fusion of the radius and ulna also makes this syndrome distinct from the thrombocytopenia with absent radii (TAR) syndrome.