Sirenomelia.

Sirenomelia is a rare malformation of caudal part of embryo. It is characterised by complete or partial fusion of the legs into a single lower limb. Abnormalities of the kidneys, large intestines and genitalia are common. Sirenomelia cases have only one umbilical artery and one vein. Upper body birth defects are rare and include abnormalities of heart, lungs, arms, spine and brain. Here we report a case of sirenomelia with uncommon upper body birth defects involving right forearm and hand, and the rib cage. Vascular steal phenomenon cannot explain the upper body birth defects.