Prevalence of mutations in TSHR, GNAS, PRKAR1A and RAS genes in a large series of toxic thyroid adenomas from Galicia, an iodine-deficient area in NW Spain.

Objective: Toxic thyroid adenoma (TA) is a common cause of hyperthyroidism. Mutations in the TSH receptor (TSHR) gene, and less frequently in the adenylate cyclase-stimulating G alpha protein (GNAS) gene, are well established causes of TA in Europe. However, genetic causes of TA remain unknown in a small percentage of cases.

Pendred syndrome in two Galician families: insights into clinical phenotypes through cellular, genetic, and molecular studies.

Context: We studied two families from Galicia (northwest Spain) with Pendred syndrome (PS) and unusual thyroid phenotypes. In family A, the proposita had a large goiter and hypothyroxinemia but normal TSH and free T3 (FT3). In family B, some affected members showed deafness but not goiter.