Medullary carcinoma familial thyroid (medullary thyroid carcinoma Familial -FMTC-) - Gen RET

Medullary thyroid family (MCTF) is the only thyroid neoplasia that develops from the C cells of the thyroid gland. In 75% of cases the medullary thyroid carcinoma occurs sporadically and in the remaining 25% it is inherited with an autosomal dominant inheritance and practically complete penetrance. Only 20% of FMTC cases medullary carcinoma presents isolated. In the remaining 80% of cases the presence of medullary carcinoma combined with the development of tumors in other organs in the syndrome called Multiple Endocrine Neoplasia type 2 (MEN2), in which two subtypes MEN2A and MEN2B differ - see Endocrine Neoplasia multiple Type 2 (MEN2) - RET gene.

The cause of MCTF is the presence of activating germline mutations in the RET protooncogene, located on the long arm of chromosome 10 (10q11.2). This gene encodes a protein involved in signaling within cells. This protein appears to be essential for normal development of various types of nerve cells, including neurons and enteric autonomic nervous system. The RET protein is also required for normal kidney development and spermatogenesis. Furthermore, this protein interacts with specific factors outside the cell and receives signals that help the cell to respond to its environment. When molecules that stimulate growth and development bind to the protein, a complex cascade of chemical reactions within the cell is triggered. These reactions induce the cell to respond to its environment, for example, dividing or maturing.

Most mutations responsible FMTC cases replaced amino acids in the protein encoded by RET gene. Approximately 85% of these changes are located on exons 10 and 11. These changes facilitate receptor dimerization independently of ligand binding, resulting in constitutive activation of the receptor.

Medullary thyroid family (MCTF) is inherited as an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient for the disease to be expressed. In most cases, an affected person has a parent with the disease.

Tests in IVAMI: in IVAMI perform detection of mutations associated medullary thyroid family concarcinoma (MCTF), by complete PCR amplification of the exons of the RET gene, and subsequent secuenciación.Dado that 85% of mutations associated MCTF are in exons 10 and 11 is recommended to start the study by them, thereby reducing time and cost, and if not, proceed by sequencing the remaining exons.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).