Familial pituitary adenomas - who should be tested for AIP mutations?

Familial Isolated Pituitary Adenomas (FIPA), an autosomal dominant disease with low penetrance is being increasingly recognized. FIPA families can be divided into two distinct groups based on genetic and phenotypic features. Patients with mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene are characterized by young-onset somatotroph or lactotroph macroadenomas, while in the other, larger group of FIPA patients with typically adult-onset disease and more varied adenoma types, no causative gene(s) has been identified. Young-onset macroadenoma patients can also be identified with germline AIP mutation without an apparent family history. Further data and longer follow-up are necessary to establish formal guidelines, but the current data suggest genetic screening of the AIP gene in patients with a pituitary adenoma and no other associated features who have (i) a family history of pituitary adenoma, (ii) childhood-onset pituitary adenoma or (iii) a pituitary somatotroph or lactotroph macroadenoma diagnosed before the age of 30 years.