Aganglionosis: associated anomalies.

In a series of 21 patients with aganglionosis there were five with associated anomalies (24%). These included trisomy 21, Smith-Lemli-Opitz syndrome type II, persistent Müllerian duct syndrome, supernumerary digits and segmental hypopigmentation. This high incidence may be due to sample bias, but clinicians are encouraged to carefully follow their aganglionic patients as there may be under-reporting of associated anomalies. Knowledge of these anomalies can help in the management of individual patients and subsequent pregnancies. In addition these diverse associated anomalies suggest that as well as sometimes being part of a vagal neural crest deficiency, aganglionosis can be part of a generalized mesenchymal defect in embryonic development. There are probably several genes involved.