Embryological and Pathophysiological Perspectives on a Rare Association of Sirenomelia with Anencephaly and Spina Bifida.

Sirenomelia is a severe developmental anomaly that manifests as the existence of a single lower limb due to fusion or the absence of one or more lower limb bones. We report a case of sirenomelia that occurred in conjunction with anencephaly and spina bifida. Numerous systems, including the genitourinary and gastrointestinal systems, have been implicated in the condition. In the present case, a single kidney, a single ureter, and an inflated and blind sigmoid colon were found following fetal dissection. In addition, the umbilical cord was histologically examined and revealed the presence of a single umbilical artery and vein. It is vital to detect abnormalities early, which can be performed by ultrasonography, in order to alleviate parents' emotional stress.