The review of clinical files of individuals in each group allowed the integration of clinical, laboratory, and semiological data conducting to the conclusion that all but one patient in G1 had a diagnosis of acromegaly (10 already submitted to surgery, five awaiting surgery); the exception was a patient with a macro prolactinoma submitted to the suppression test because of an abnormal basal GH despite a normal IGF-1. This evidence concerns the gene GH1 and acromegaly.