Proximal Radio-ulnar Synostosis With Bone Marrow Failure Syndrome in an Infant Without a HOXA11 Mutation

This report summarizes the clinical management of an infant with a proximal radio-ulnar synostosis and inherited bone marrow failure syndrome (PRUS/IBMFS). Molecular studies were negative for the characteristic HOXA11 mutation described earlier. He was successfully treated with a non-myeloablative hematopoietic stem cell transplantation from an human leukocyte antigenidentical sibling donor at the age of 3 months. We reviewed the literature on PRUS/IBMFS with an emphasis on the current understanding of the molecular mechanisms involved in the disease pathogenesis. Absence of the HOXA11 mutation in this case implies that molecular mechanisms beyond the HOXA11 gene, yet to be discovered, may contribute for the development of PRUS/IBMFS.