RET mutations in multiple endocrine neoplasia type 2 and Hirschsprung disease.

Mutations in the RET proto-oncogene have been found in a large proportion of families affected by the multiple endocrine neoplasia type 2 syndrome and in familial and sporadic Hirschsprung disease. This review discusses the role of the RET receptor tyrosine kinase in the etiology of these dominantly inherited disorders of neural crest development. In addition, the role of genetic screening is considered in the identification and clinical management of individuals at risk for these diseases.