The clinical presentations caused by hormone overproduction in PAs are closely related to the pituitary cell types, as follows: corticotropin-secreting corticotroph adenomas result in Cushing’s disease, growth hormone (GH)-secreting somatotroph adenomas result in acromegaly, prolactin-secreting lactotroph adenomas result in hyperprolactinemia, and thyrotropin-secreting thyrotroph adenomas result in hyperthyroidism (2). The gene discussed is GH1; the disease is familial isolated pituitary adenoma.