Germ-line mutations of the RET proto-oncogene in multiple endocrine neoplasia type 2A

Multiple endocrine neoplasia type 2A (MEN 2A) is a prevalent cancer syndrome affecting the neural ectodermal derived tissues. Medullary Thyroid Carcinoma (MTC) and phaeochromocytoma are characteristic of the MEN 2A. At lower levels of the human thyroid and in MTC and phaeochromocytoma, a receptor tyrosine kinase gene, the RET photo-oncogene, is invested in the DNA segment. A recent study identified 20 RET proto-oncogene missense mutations from 23 apparently distinct MEN 2A families, but not in 23 normal controls. Of the 20 mutations, 19 affect similar conserved cysteine residue of the RET extracellular and transmembrane domains at the boundary.