RET c.1901G>A and Novel SLC12A3 Mutations in Familial Pheochromocytomas

Abstract

Familial PHEOs (pheochromocytomas) are inherited as an autosomal dominant trait, and inherited PHEOs can be one clinical phenotype of clinical syndromes, such as multiple endocrine neoplasia type 2A (MEN2A). In recent years, there has been a lot of controversy about the factors affecting the penetrance of PHEOs in MEN2A, of which the effects of RET (rearranged during transfection) proto-oncogene mutations are the primary concern. In this report, we performed genetic screening of patients in one family presenting with PHEOs and found they carried a RET c.1901G>A mutation. They were ultimately diagnosed with familial MEN2A. We found that MEN2A patients with the RET c.1901G>A mutation tended to have bilateral PHEOs that appeared earlier than medullary thyroid carcinoma. Genetic analysis showed that the patients also carried novel SLC12A3 (solute carrier family 12 member 3) variants, which are highly associated with Giteman syndrome. The results of protein structure prediction models suggest this SLC12A3 mutant has altered both the protein structure and the interaction with surrounding amino acids. Further studies of the phenotypes and related mechanisms of the gene mutations are required to guide individual assessment and treatment.