Identifying which gene is central to the diagnosis of Familial Medullary Thyroid Carcinoma?

Familial Medullary Thyroid Carcinoma (FMTC) is primarily associated with mutations in the RET proto-oncogene. This gene plays a critical role in cell signaling pathways linked to cell growth and differentiation. In particular, mutations in RET are implicated in Multiple Endocrine Neoplasia (MEN) syndromes, which often include medullary thyroid carcinoma as a key component of the disease.

Patients with FMTC typically have a hereditary predisposition to develop this type of thyroid cancer, and the identification of mutations in the RET gene allows for genetic testing and risk assessment for family members. This genetic connection underscores the significance of RET in the pathogenesis of FMTC, allowing for early surveillance and intervention strategies in at-risk individuals.

The other options, while associated with different conditions or cancers, do not specifically relate to Familial Medullary Thyroid Carcinoma. P53 is more commonly associated with a variety of cancers due to its role as a tumor suppressor. XPA is involved in nucleotide excision repair and is linked to xeroderma pigmentosum, while BRCA1 mutations are primarily associated with breast and ovarian cancers rather than thyroid tumors. Thus, the focus on RET is paramount in the context of FMTC diagnosis