XRCC3 and familial papillary or follicular thyroid carcinoma: We did not find mutations in: genes previously described in syndromic FNMTC (APC, PTEN, WRN, DICER1 and PRKAR1A), rearranged genes (NTRK, PPARG), DNA repair genes (XRCC1, XRCC3), genes involved in the development of the thyroid gland (PAX8, JAG1, CDC42, GSTM1, GSTT1, SRGAP1, TERT, THRB, AKT1, SEC23B, ESR2, NKX2, TBL1X), genes previously described in the literature in nonsyndromic FNMTC (HABP2, TTF1, THADA, SEC23B, FOXE1, KLLN, MAP2K5), oncogenes (RET, MET, KIT, MERTK), nor genes that have been found in TC with somatic mutations (BRAF, NRAS, TP53, CDKN2A, ALK, ATF4).