Extensive study provides new information on the genetic background of endometriosis

Very little is known about the causes of endometriosis, and studying genetics by comparing the DNA code in women with and without the disease can help in the understanding of the biological processes that underlie the onset and progression of the disease.

The study revealed compelling evidence of a shared genetic basis for endometriosis and other types of pain seemingly unrelated to endometriosis, including migraine, back pain and multi-site pain. In addition, it emerged that ovarian endometriosis has a different genetic basis from other subtypes of endometriosis.

In the largest genome-wide study ever conducted, the researchers found 42 areas across the genome that harbour genetic variants that increase risk of endometriosis. By linking these variants to the profiles of molecules in endometrium and blood, they identified a range of genes that were differently expressed in these tissues and therefore had a likely role in disease development.

Outi Uimari, a specialist in obstetrics and gynaecology who was in charge of the Finnish part of the study, says that endometriosis research is active both globally and in Finland. “Thanks to research, endometriosis is understood to be a common women’s disease that often begins in adolescence, contrary to what was previously thought. Genetic research strengthens the understanding of the heredity of the disease and, therefore, its family history. All this information helps to develop work with patients, where we have made great strides in Finland in recent years.”

The list of genome areas and genes identified in the study is important for the development of new treatments, better targeted for subtypes of the disease. The results open up opportunities to design new drug therapies and new non-hormonal treatments focused on pain, or to repurpose existing pain treatments, for endometriosis.

Endometriosis is a serious chronic inflammatory disease with extensive implications on the quality of a woman’s life. This severe inflammatory condition occurs in 5–10% of women of reproductive age (190 million globally) and can cause constant and intense pelvic pain, fatigue, depression, anxiety and infertility. It is characterised by the presence of tissue that resembles the uterus lining (endometrium) outside the uterus These endometriotic deposits are primarily located on organs within the pelvis (e.g. ovaries, pelvic surfaces and ligaments, bowel or bladder), although more rarely they can also be found outside the pelvis.

The huge impact on the health of many women is compounded by the fact that endometriosis can only reliably be diagnosed through surgery and sometimes imaging, and often takes many years to diagnose – eight years on average from first symptoms. Treatment is limited to repeated surgeries and hormonal treatments with many side-effects that may not allow women to get pregnant.

Research article: Rahmioglu, N., Mortlock, S., Ghiasi, M. et al. The genetic basis of endometriosis and comorbidity with other pain and inflammatory conditions. Nat Genet 55, 423–436 (2023). https://doi.org/10.1038/s41588-023-01323-z