SUMMARY The genetic, clinical, and necropsy findings of 2 brothers with the prune belly anomaly are presented and the literature reviewed. The combined data emphasise the clinical and genetic heterogeneity of the disorder and show that in at least some instances a heritable component may be the primary insult. The most likely heritable explanation involves a two-step autosomal dominant mutation with sex-limited expression that partially mimics X-linkage.The triad of deficient abdominal musculature, urinary tract and renal anomalies, and cryptorchidism has been recognised for many years (