Small bowel malrotation in each of a pair of identical twins.

A rare case of small bowel malrotation occurring in each of a pair of identical twins is presented. The conflicting evidence in the literature regarding possible hereditary influences is reviewed. This case raises the intriguing question of whether this disorder is due to a prenatal insult, an autosomal recessive gene, or a new autosomal dominant mutation. If one identical twin is found to have a small bowel malrotation, the authors strongly advise that the other twin be screened.