MUTATIONS OF THE RET PROTOONCOGENE IN HIRSCHSPRUNGS-DISEASE

HIRSCHSPRUNG'S disease (HSCR)1 is a common condition (1 in 5,000 live births) resulting in intestinal obstruction in neonates2 and megacolon in infants and adults3. This disease has been ascribed to the absence of autonomic ganglion cells, which are derived from the neural crest, in the terminal hindgut4. Segregation analyses have suggested incompl etely penetrant dominant inheritance in familial HSCR5. Recently, a ge ne for HSCR has been mapped to chromosome 10q11.2 (refs 6, 7). No reco mbination was observed between the disease locus and the locus for the RET proto-oncogene8, a protein tyrosine kinase gene expressed in the cells derived from the neural crest9,10. Here we report nonsense and m issense mutations in the extracellular domain of RET protein (exons, 2 , 3, 5, and 6) in six unrelated probands and show that the mutant geno types segregate with the disease in HSCR families. Mutations of RET ha ve been previously reported in multiple endocrine neoplasia type 2A (M EN 2A)11,12. Thus, germ-line mutations of the RET gene may contribute either to developmental anomalies in HSCR or to inherited predispositi on to cancer in MEN 2A.