MEN1 and growth hormone-producing pituitary gland adenoma: However, some other families with isolated acromegaly do not have abnormalities of the MEN1 gene (Lemos and Thakker, 2008), even though segregation analysis in families with isloated acromegaly and LOH studies of somatotrophinomas indicated that the gene was likely to be located on chromosome 11q13 (Soares et al., 2005).