Abstract 821 Poster Session IV, Tuesday, 5/4 (poster 193)

Introduction: Hirschsprung disease (HD) is an heterogenous disorder. HD type 2 (HSCR2, OMIM 600155) maps to chromosome 13q22. The endothelin-B receptor gene (EDNRB)maps to the same region. A dosage sensitive mutation in this gene is responsible for HSCR2. Families with mutations in this gene usually exhibit autosomal recessive transmission affecting predominantly males. This critical region was found to be deleted in an infant with HD in association with a number of several other anomalies. An association of HD with 13q deletions is a rare occurrence.

Case report: F.G. was the 2722 g product of a 39 wks. unremarkable pregnancy, delivered to a 28 years old primigravida West African mother. She passed no stool for several days, fed poorly and was maintained on TPN until 21st day of life when a biopsy revealed an aganglionic 34.5 cm segment of colon from the rectum to the splenic angle. Colon resection of the aganglionic segment followed. Her clinical examination at six months revealed a stigmatized infant. Her weight was 5 kg, length 60.5 cm and head circumference 41 cm. She was markedly dolicochephalic with an occipital shelf. The eye findings were steel grey irides with elliptical pupils, slight proptosis and epicanthi. She had a left Sydney line, the anus was anteriorly displaced and the labia minora was hypoplastic. A dilated eye exam was normal. Ultrasound of kidneys and collecting system, pelvic MRI and CT scan and vaginogram revealed no GU anomalies. The peripheral blood karyotype revealed a 13q deletion extending from 14.3 to 22.2.

Discussion: There has been a total of 10 patients reported with 13q interstitial deletion and intestinal anomalies; 6 of these had HD. Two of these had also bilateral retinoblastoma and all had multiple additional anomalies. The gastrointestinal and eye anomalies noted in our patient are similar to previous reports. The presence of HD in this female patient may be explained by the presence of a mutation in the EDNRB gene in the normal homolog. Molecular studies will help to clarify this hypothesis.