In almost 50% of patients, a genetic cause can be identified, mainly familial isolated pituitary adenoma caused by the aryl hydrocarbon receptor-interacting protein (AIP) variants, and X-linked acro-gigantism (X-LAG) or McCune Albright syndrome (Rostomyan et al. 2015). This evidence concerns the gene AIP and X-linked acrogigantism due to Xq26 microduplication.