Detection of DNA copy number changes in human endometriosis by comparativegenomic hybridization

Endometriosis is characterized by infertility and pelvic pain in 10-15% of women of reproductive age. The genetic events involved in endometriotic cel l expansion remain in large part unknown. To identify genomic changes invol ved in development of this disease, we examined a panel of 18 selected endo metriotic tissues by comparative genomic hybridization (CGH), a molecular c ytogenetic method that allows screening of the entire genome for chromosoma l gains and/or losses. The study was performed on native, nonamplified DNA extracted from manually dissected endometriotic lesions. Recurrent copy num ber losses on several chromosomes were detected in 15 of 18 cases. Loss of chromosome 1p and 22q were detected in 50% of the cases. Additional common losses occurred on chromosomes 5p (33%), 6q (27%), 7p(22%), 9q (22%), 16 (2 2%) as well as on 17q in one case. Gain of DNA sequences were seen at 6q, 7 q and 17q in three cases. To validate the CGH data, selective dual-color FI SH was performed using probes for the deleted regions on chromosomes 1, 7 a nd 22 in parallel with the corresponding centromeric probes. Cases showing deletion by CGH all had two signals at 1p36, 7p22.1 and 22q12 in less than 30% of the nuclei in comparison to the double centromeric labels found in m ore than 85% of the cells. These findings indicate that genes localized to previously undescribed chromosomal regions play a role in development and p rogression of endometriosis.