Sirenomelia: four further cases with discussion of associated upper limb defects.

Sirenomelia, also known as the 'mermaid malformation/syndrome', is a rare, serious congenital anomaly characterized by variable degrees of fusion of the lower limbs and associated severe malformations of the lower vertebral and genitourinary systems. In this report, we describe a series of African patients with sirenomelia. We present the clinical and radiological features of four black South African patients and illustrate some of the rarer associated abnormalities, which include asymmetrical upper limb defects, not confined to the radial ray. The clinical phenotypic overlap between caudal dysgenesis, VACTERL association and sirenomelia in our patients is highlighted, lending support to the theory that these entities may be different manifestations of a single pathogenic process.