MEN 2A and MEN 2B syndromes are associated with germline mutations in:

D. The RET proto-oncogene

DISCUSSION: Germline mutations in the RET protooncogene, a receptor tyrosine kinase that maps to chromosome 10, are associated with MEN 2A and MEN 2B syndromes. Homozygous loss of the tumor suppressor gene p53 is associated with the Li-Fraumeni syndrome, and mutations of p53 are present in a variety of human neoplasms. Point mutations in the H-ras gene are associated with carcinoma of the colon, lung, and pancreas. Amplification of the N-myc gene, when present in neuroblastoma, suggests a poorer prognosis.