Distal foregut atresias in consecutive siblings and twins in the same family.

The distal foregut comprises the antrum of the stomach and supra-ampullary region of the duodenum. In this part of the gut, intraluminal mucosal diaphragms, webs, membranes (type I), and rarely solid cord (type II) atresias are occasionally seen in clinical practice. Due to increased awareness, the number of reported cases has increased in recent years. These foregut lesions are known to have a strong genetic association. Both antral (AA) and duodenal atresias (DA) may occur as potentially curable sporadic cases or in combination with lethal malformations such as hereditary multiple gastrointestinal atresias affecting the fore-, mid-, and hindgut. The association of AA and junctional epidermolysis bullosa lethalis is well-known. We describe an unusual occurrence of foregut atresias in two consecutive siblings and a pair of monozygous twins. The involvement of four siblings in a single family is extraordinary and as yet unreported. This cluster of cases not only lends a strong support to a genetic origin, but also the mode of transmission, despite the absence of a history of consanguinity. It indicates that atresia of the gastric antrum and supra-ampullary DA are etiologically closely related. It is also possible that the discordant expression in the twins could be a pleiotropic effect of the same genetic factor. Attempts are made to explain the possible pathogenesis of this unusual atresia and relate it to other associated anomalies.