A clinically novel AIP mutation in a patient with a very large, apparently sporadic somatotrope adenoma

Abstract

Heterozygous germline inactivating mutations in the aryl hydrocarbon receptor-interacting protein ( AIP ) gene lead to pituitary adenomas that most frequently present in the setting of familial isolated pituitary adenoma syndrome, usually as somatotropinomas and prolactinomas. More recently, they have been found in a significant percentage of young patients presenting with pituitary macroadenoma without any apparent family history. We describe the case of a 19-year-old man who presented with a gigantic somatotropinoma. His family history was negative. His peripheral DNA showed a heterozygous AIP mutation (p.I13N), while tumor tissue only had the mutated allele, showing loss of heterozygosity (LOH) and suggesting that the mutation caused the disease.