ORIGINAL ARTICLE Gynaecology DNAmethylation of HOXA10 in eutopic and ectopic endometrium

study question: Does the methylation status of the promoter region of the HOXA10 gene differ in eutopic and ectopic endometrium? summaryanswer: Theeutopicendometrium inwomenwithendometriosis is significantlymoremethylatedwhencomparedwith controls. what is known already: Expression of the HOXA10 gene, which is important for successful implantation, is reduced in women affected by endometriosis. study design, size and duration: A pilot study was carried out including 18 women admitted for surgery for endometriosis-related pain (cases) and 12 women admitted for surgery because of non-endometriotic disease (control). Sample collection and analysis were performed between November 2010 and July 2013. participants/materials, setting, methods: Endometrial tissue (eutopic and ectopic) underwent sodium bisulfite DNA modification, PCR amplification of two regions of the HOXA10 promoter and pyrosequencing analysis. main results and the role of chance: The eutopic endometriumofwomenwith endometriosis was significantlymoremethy-lated compared with endometrium from the control group (sequence 1: 8.68 % in cases and 6.25 % in the control group: P 0.037, sequence 2: 11.89 % in cases and 9.25 % in the control group: P 0.032). The eutopic endometriumwas significantly moremethylated than the ectopic tissue in patients with endometriosis (mean difference 23.6 sequence 1: P 0.001 and 26.0 sequence 2: P 0.0001). limitations, reasons for caution: The study had a limited sample size and the fertility status of the majority of patients in our study was unknown.