To date, the number of molecular genetic factors unequivocally linked to pituitary tumours can be counted on the fingers of one hand: (1) GNAS1 activation in acromegaly; (2) the MENIN and p27Kip1 (CDKN1B) mutations associated with multiple endocrine neoplasia type 1; (3) mutations of PRKA1RA with loss of 17q22-24 in Carney complex, and (4) aryl hydrocarbon receptor interacting protein gene mutations in 15% of familial isolated pituitary adenomas and 50% of familial isolated acromegaly.
The relatively high age at diagnosis, as well as its sporadic presentation, suggests that these patients are carriers of mutations with reduced pathogenicity. p27(KIP1) is unlikely to represent the common unifying nonendocrine etiology for acromegaly and cancer.