Which of the following gene defect is associated with the development of medullary carcinoma of thyroid-
Thyroid carcinoma

The major types of carcinoma and their relative frequency:-

  Papillary carcinoma →  75% to 85% (most common)  
  Medullary carcinoma  → 5%
  Follicular carcinoma → 10% to 20%            
  Anaplastic carcinoma → < 5%

Most thyroid carcinomas are derived from the follicular epithelium , except for medullary carcinoma which is derived from the parafallicular or 'C' cells .
Genetic factors in different thyroid carcinoma
Papillary  →  Tyrosine kinase receptors RET or NTR K1 

          RAS mutation
          BRAF oncogene

Follicular  → RAS oncogene (NRAS, HRAS and KRAS)

                   PAX8- PPARr 1 translocation

Medullary → RET proto oncogene.
Familial medullary cancers account for most inherited cases of thyroid cancer.
Familial nonmedullary thyroid cancers (papillary and follicular) are very rare.
RET Proto Oncogene
Fap gene.
Rb gene
BRCA 1 gene