Microsatellite DNA assays reveal an allelic imbalance in p16(Ink4), GALT, p53, and APOA2 loci in patients with endometriosis

Objective: To detect allelic imbalance on specific genetic loci occurring in endometriosis. Design: Microsatellite analysis. Setting: Paraffin-embedded tissues histologically confirmed as endometriotic or normal endometrium. Patient(s): Premenopausal women undergoing laparoscopy for suspected endometriosis. Intervention(s): Laparoscopic excision of specimens. Main Outcome Measure(s): Allelic imbalance and alterations of intensity of microsatellite alleles. Result(s): Five of 17 microsatellite DNA markers (29.4%) showed allelic imbalance. Eight samples (36.4%) showed allelic imbalance in at least one locus. Loci 9p21, 1q21, and 17p13.1 exhibited imbalance in 27.3%, 4.5%, and 4.5%, respectively. A 3-fold increase of the fractional allelic loss was observed from disease stage II to III and IV, whereas only 1.3-fold was found between patients of 41-50 and 20-40 years. Conclusion(s): We found that loss of heterozygosity on p16(Ink4), GALT, and p53, as well as on APOA2, a region frequently lost in ovarian cancer, occurs in endometriosis, even in stage II of the disease. The occurrence of such genomic alterations may represent important events in the development of endometriosis. The 9p21 locus may contain a gene associated with the pathogenesis of the disease, and therefore its loss may be a prognostic marker of the disease. (C) 2001 by American Society for Reproductive Medicine.