The Pathogenesis of Radial Ray Deficiency in Thrombocytopenia-Absent Radius (TAR) Syndrome.

The genetic basis of thrombocytopenia-absent radius (TAR) syndrome was recently identified to be related to the RBM8A gene. The encoded protein (known as the Y14 protein) is widely expressed in human cells (including osteoblasts) and plays several essential intracellular functions. Hence, the pathogenesis of radial ray deficiency in thrombocytopeniaabsent radius syndrome remains a mystery. The current paper reviews the pathogenesis of the clinical features of thrombocytopenia-absent radius syndrome and offers a hypothesis of pathogenesis through attenuation of the Fibroblast Growth Factor 8 signal in the mesoderm because of an increased degradation of the Fibroblast Growth Factor Receptor 1.