Mitochondrial DNA Haplogroup R Confers a Genetic Risk Factor for Intrauterine Adhesion in Han Women Population

To determine whether a specific mitochondrial DNA (mtDNA) haplogroup is implicated in the pathogenesis of intrauterine adhesion (IUA).Peripheral blood samples were collected from 486 women with (case group, n = 154) and without IUA (control group, n = 332) at the Women's Hospital, Zhejiang University School of Medicine. Genomic DNA was extracted from the blood, and the mtDNA haplogroups of Han women M, N and R were determined by sequencing hypervariable mtDNA segments and testing diagnostic polymorphisms in the mtDNA coding region.Women with mtDNA haplogroup R had an independently increased genetic risk factor for IUA with an OR 1.77 (95% CI 1.16-2.70, p = 0.009) compared with women without. Moreover, repeated intrauterine surgery within 1 month and number of intrauterine operations were both significantly associated with IUA (p < 0.001).These results suggest that mtDNA haplogroup R, one of the main mtDNA haplogroups in Han population, is a strong independent genetic risk factor for women with IUA.