A Novel MECOM Variant Associated with Congenital Amegakaryocytic Thrombocytopenia and Radioulnar Synostosis

To the Editor

Congenital radioulnar synostosis (RUS) is a rare developmental anomaly of proximal fusion of the radius and ulna, resulting in limited pronation and supination of the forearm. It may accompany other abnormalities in the skeleton, kidney, heart and aneuploidy syndromes^1,2. A subset of patients with RUS present with bone marrow failure (BMF) syndromes, characterized by amegakaryocytic thrombocytopenia (RUSAT), progressing to myelodysplasia and pancytopenia^2,3. The hematological manifestations are quite variable, with some presenting with severe BMF in childhood, while others are mild and may not present until adulthood.