Hyperplastic pituitary gland, high serum glycoprotein hormone alpha-subunit, and variable circulating thyrotropin (TSH) levels as hallmark of central hypothyroidism due to mutations of the TSH beta gene. - Bonomi,M.; Proverbio,M.C.; Weber,G.; Chiumello,G.; Beck-Peccoz,P.; Persani,L. (J Clin Endocrinol Metab, 2001)