Isolated imperforate anus in dizygotic twins
The authors report an isolated imperforate anus case in a dizygotic twin, which is the first re-ported case in the literature, the other reported cases were in monozygotic twins. The literature review points to a multifactorial etiology in which environmental triggers interact with genetic susceptibility; in most of these cases, the defect was low in monozygotic twins, as in this dizygotic twin's case. Numerous documented familial cases pointed to an underlying genetic characteristic that is still mostly unknown, but all these cases presented as monozygotic twins, which supports the genetic factor. Our case was the first reported case in the literature of a dizygotic twin with an isolated imperforate anus who has an older sibling who presented at birth with anal stenosis.