Gonadotropin-releasing hormone-associated peptide gene sequences in women with hyperprolactinemia

Objective: To determine if mutations in the structural gene for gonadotropin-releasing hormone (GnRH)-associated peptide are present in women with hyperprolactinemia. Design: Patients with hyperprolactinemia and controls were studied retrospectively for GnRH-associated peptide gene mutations. Settings: Patients seen in a clinical setting were studied at a medical school laboratory setting. Patients: Fifteen women with hyperprolactinemia and two fertile controls with normal prolactin levels were studied. Interventions: Genomic deoxyribonucleic acid (DNA) was extracted from each patient and subjected to Southern blot analysis and polymerase chain reaction (PCR). For Southern blot analysis, DNA was digested with EcoRI, XbaI, BglII, PstI, and BamHI and hybridized to two DNA probes for GnRH-associated peptide. Exons II to IV, which encode for the structural gene, were amplified by PCR. Main Outcome Measures: Fragment sizes from autoradiographs were compared among patients and controls. Amplified PCR products of exons II to IV of the GnRH-associated peptide were also compared. Results: No large deletions, insertions, or polymorphisms were identified in women with hyperprolactinemia or controls by Southern blotting. Each of the exons was present and of normal size by PCR in the study patients and controls. Conclusions: No large deletions of the GnRH-associated peptide gene appear to be present in our patients with hyperprolactinemia. Small deletions, insertions, or point mutations are not excluded by this analysis.