Mondo Description Hirschsprung disease-deafness-polydactyly is an extremely rare malformative association, described in only two siblings to date, and characterized by Hirschsprung disease (defined by the presence of an aganglionic segment of variable extent in the terminal part of the colon that leads to the symptoms of intestinal obstruction including constipation and abdominal distension), polydactyly of hands and/or feet, unilateral renal agenesis, hypertelorism and congenital deafness. There have been no further descriptions in the literature since 1988.