An unusual presentation of sacral agenesis in a newborn baby.

A potentially difficult situation can arise when a sick newborn baby presents with a common clinical sign that subsequently turns out to be a manifestation of a rare condition. The baby's birth sometimes results in the diagnosis of a new condition in other members of the family. Necrotising enterocolitis is the commonest surgical condition among babies in the neonatal intensive care unit (NICU). We report a case where abdominal distension in an acutely ill baby at high risk of necrotising enterocolitis masqueraded as an unusual presentation of familial sacral agenesis.