Diagnostic and genetic aspects of congenital radial ray deficiency

Congenital anomalies of the radial ray, with aplasia or hypoplasia of the radius and/or thumb, occur as isolated deformities or as part of a syndrome that includes other malformations. Cases of isolated radial ray deficiency are usually nongenetic. However, radial ray deficiency occurs in hereditary syndromes such as Holt-Oram and Fanconi's anemia. Other syndromes with radial ray deficiency occur in chromosomal aberrations such as trisomy-18 or may result from a teratogenic factor such as thalidomide embryopathy. The Vater and Vacterl association of anomalies are examples of idiopathic nongenetic syndromes. During the years 1973-1983, eight cases of newborn babies with radial ray deficiency were diagnosed and treated. These cases represent the full spectrum of conditions associated with this anomaly. The importance of prenatal detection and of accurate postnatal diagnosis are stressed because of their relevance to treatment, prognosis and genetic counselling.