This document summarizes congenital radial club hand deformities. It describes the classification system including types I-IV based on the severity of radial dysplasia. Type IV is the most common, involving total absence of the radius. Associated anomalies can include deficiencies of the thumb, scaphoid, trapezium and other carpal bones. Muscles on the radial side like the brachialis and brachioradialis are often absent or hypoplastic. Associated syndromes that sometimes occur include Holt-Oram syndrome, Fanconi anemia, and thrombocytopenia-absent radius syndrome. Surgical treatment requires consideration of any associated anomalies.