Olsen KW, Castillo-Fernandez J, Cho Chan A, et al. - This study was undertaken to determine if epigenetic profiles of mural granulosa cells (MGC) and leukocytes from women with diminished ovarian reserve (DOR) vary from those of women with normal or high ovarian reserve. The sample consisted of 119 women of various ages and ovarian reserve status (antimüllerian hormone level) who provided blood samples and MGC. In women with DOR, the somatic cells of human ovarian follicles have a distinctive epigenetic profile. Premature aging is demonstrated by a high frequency of epimutations. In the leukocyte epigenetic profile, ovarian reserve status was not reflected.