Frequency of familial pituitary adenoma syndromes among patients with functioning pituitary adenomas in a reference outpatient clinic

Introduction Pituitary adenomas (PA) occur mainly as sporadic disease, but familial syndromes are found in approximately 5% of cases. Identification of these syndromes is important in order to diagnose individuals at risk at an earlier stage. Aims To evaluate the frequency of familial PA in a reference outpatient clinic devoted to PA treatment and to identify family members suspected to have pituitary disease. Methods Patients with PA were interviewed with respect to the presence of family members with diagnosis of PA or with signs or symptoms suggestive of them. The family members who had a clinical picture suggestive of pituitary disease were further evaluated in an attempt to identify new PA cases. In families with familial disease, the AIP gene was sequenced. Results 262 patients were evaluated and familial syndrome was found in 13 (5%). Ten (3.8%) patients had familial isolated PA (FIPA) and three (1.2%) had multiple endocrine neoplasia type 1. After evaluation of family members' symptomatology, 110 were considered suspected of having pituitary disease, but only 24 participated in the study. Of these 24, 1 was diagnosed with a corticotropinoma. AIP mutations were found in 20% of FIPA families. Conclusion We found a frequency of familial PA similar to that previously described, as well as a similar frequency of AIP mutations among FIPA families. An active search of the affected family members was able to identify one case of Cushing's disease. Patients should be aware of pituitary disease's clinical picture to identify possibly affected family members.