Genetic factors involved in the co‑occurrence of endometriosis with ankylosing spondylitis (Review)

Previous research has revealed an association between endometriosis and various autoimmune diseases, while recent data suggest, for the first time, an association between endometriosis and the risk of developing ankylosing spondylitis (AS). AS, the prototype of spondyloarthritides diseases, is a systemic, chronic, immune‑mediated inflammatory arthritis, which primarily affects the spine and sacroiliac joints, as well as the axial skeleton with or without extraspinal manifestations. AS is of polygenic inheritance and numerous immunologically relevant genes contribute to its development. Endometriosis is an enigmatic, relatively common, benign, estrogen‑dependent, heterogeneous gynecological disease, influenced by multiple genetic, epigenetic and environmental factors. It is characterized by the growth of endometrial tissue occurring in sites other than the uterine cavity, most commonly in the pelvic cavity, including the ovaries and the uterosacral ligaments, affecting up to 10% of the female population of childbearing age, causing pain and infertility. The present review discusses whether a partially shared genetic background may explain the co‑occurrence of these disorders, as well as potential similarities regarding the underlying pathogenetic mechanisms and specific molecular and cellular pathways.