Add Genetic Variants to the Risk Factors for Endometriosis
Along with age, not having children, and problems with menstruation, scientists have identified two genetic variants as a risk factor for developing endometriosis. Researchers from several institutions have found clues to the origin of this common gynecological condition.
Two genetic variants increase the risk of endometriosis
The Endometriosis Association reports that endometriosis affects at least 6.3 million women and girls in the United States, 1 million in Canada, and millions more around the world. This painful gynecological condition occurs when the lining of the uterus (endometrium) develops outside the uterus, most often in the abdomen, the outside of the uterus, the lining of the pelvic cavity, or on the ovaries, fallopian tubes, and ligaments that support the uterus. Endometrial growths may also appear on the bladder, bowel, vagina, cervix, or vulva.
This endometrial tissue develops into lesions that respond to the menstrual cycle just like the tissues in the uterus. The blood and tissue shed from these endometrial lesions have no way to leave the body, which results in internal bleeding, pain, infertility, scar tissue formation, and bowel problems. Women with endometriosis may also experience painful urination during periods, pain during sex, fatigue, allergies, and frequent yeast infections.
Investigators with the new study, which was conducted at the Wellcome Trust Centre for Human Genetics and the Nuffield Department of Obstetrics & Gynaecology, University of Oxford; the Queensland Institute of Medical Research, Australia; and Brigham and Women’s Hospital and Harvard Medical School, identified two genetic variants that increase a woman’s risk of developing endometriosis.
The discovery was made when the scientists compared the genomes of more than 5,500 women who had been diagnosed with the disease, with those of nearly 10,000 healthy volunteers. They identified two new genetic variants that increase the risk of developing endometriosis, especially moderate-severe disease.
According to the study’s main investigator, Dr. Krina Zondervan, a Wellcome Trust Research Career Development Fellow at the University of Oxford, “We’ve known for some time that endometriosis is heritable, but until now we have been unable to find any robust genetic variants that influence a woman’s risk of developing the disease.”
What the investigators found was a variant on chromosome 7, which appears to regulate other genes that are close by, likely those involved in the development of the womb and the endometrium. The other variant is on chromosome 1, near gene WNT4, which is important for development of a woman’s reproductive tract, especially the ovaries.
What does the addition of gene variants to the risk factor list for endometriosis mean to women? Dr. Stephen Kennedy, joint senior author of the study and head of the Nuffield Department of Obstetrics & Gynaecology, notes that “the results of this study will help towards developing less invasive methods of diagnosis and more effective treatments for endometriosis.”