Acromegaly in a family without a mutation in the menin gene

Familial pituitary tumors are rare. Only 45 cases in 20 families with acromegaly have been reported. A third of the cases (30%) is related to multiple endocrine neoplasia type 1 (MEN 1). We report two cases of acromegaly in one family with pituitary macroadenomas. A 46-year-old woman with elevated serum growth hormone (GH) and insulin-like growth factor (IGF-1) and a failure to supress GH in the glucose tolerance test underwent transsphenoidal surgery 4 years ago. Three years later her 24-year-old son also presented with typical signs of acromegaly. A pituitary macroadenoma was identified by MRT and he also underwent transsphenoidal surgery. There were no symptoms of McCune-Albright syndrome or other forms of endocrine hyperfunction in the two patients. In an attempt to identify the molecular etiology of the tumours DNA was extracted from paraffin fixed tissue from both patients. Exon 7 to 13 of the Gsp-protein and exons 1 to 10 of the menin gene were amplified by PCR. Although Gsp mutations have been identified in 40% of somatotroph tumors, direct sequencing of the PCR products showed no mutations in exons 7 to 13 of Gs alpha. Moreover no mutations were found in exons 1 to 10 of the menin gene. Therefore, molecular causes other than Gsp or menin gene mutations have to be considered as the molecular etiology of acromegaly in this family.