Prenatal identification of isolated bilateral radial dysplasia.

Radial aplasia or hypoplasia is characterized by complete or partial absence of the radius and/or radial ray structure occurring in 1:30,000 live births. It may be unilateral or bilateral of varying severity, and may be isolated or associated with other anomalies. We report an unusual case of isolated radial aplasia at 20 weeks' gestation with complete absence of the right radius and thumb associated with marked hypoplasia of the left radius. The intrauterine 2- and 3-dimensional findings, postnatal radiographic evaluation, and autopsy results are reported.