A novel germline variant in RET gene resulting in an additional cysteine in a family with familial medullary thyroid carcinoma

We describe a novel c.1765A >  T variant ofRET proto-oncogene in a family with medullary thyroid carcinoma (MTC) that predicts the creation of an additional cysteine p.(Ser589Cys) in the cysteine-rich domain. In this site only three other punctual variants have been described, giving rise to extra cysteines. We have characterized the clinical phenotype of this family. The index case was a 79-year-old woman with MTC in both thyroid lobes. This variant co-segregates in this family in four affected members. One member was operated on at 31  years of age and already presented MTC, indicating that prophylactic thyroidectomy was appropriated. Variants predicting additional cysteines are not frequent in RET, and when present, they allow us to understand their implication in the disease. According to clinical data obtained in this family, this variant could be categorized as a moderate-risk of the disease.
Source: Familial Cancer - Category: Cancer & Oncology Source Type: research