A new study suggests that certain genetic differences, passed down from ancient human ancestors, and exposure to common present-day chemicals could explain why some women are more likely to develop endometriosis.
The research, published in the European Journal of Human Genetics , could open to the door to understanding more about how the interaction between our DNA and the modern environment is linked to the condition.
Around one in ten women of reproductive age have endometriosis, a gynaecological disease that can cause severe pain and inflammation - often linked to problems with the body's immune system.
"Endometriosis has come to the forefront in recent years and a lot more people understand what it is, but it remains difficult to diagnose early and often goes untreated," said Amelia Warren who led the study as part of her Masters degree at Bournemouth University. "Ultrasounds do not usually pick up the small signs and pelvic pain is often assumed to be normal for a woman during her period. As a result, it's typically the most severe cases that get diagnosed," she added.
The Bournemouth University researchers began by reviewing previous research and identified five genes which are most likely to be linked to endometriosis. These genes are also particularly sensitive to common modern chemicals which can interfere with the bodies hormones and disrupt the immune system.
Using the NHS's Genomics England database, the team then looked for differences in these genes within 19 women who had been diagnosed with endometriosis, compared to other women without the condition.
They found six genetic variants that were more common in women with endometriosis. Some of these variations appear to have been inherited from early human ancestors, including Neanderthals and other ancient populations.
The team believe it is significant that that several of these variations occur in genes that are known to react to chemicals that were once considered harmless and are now found in plastics, cosmetics, and household products. This suggests that a combination of the inherited genetic traits and exposure to these chemicals could disrupt the body's immune system - potentially causing the inflammations associated with endometriosis.
Amelia and the research team hope that their findings can lead to a new understanding of why some women develop endometriosis and help identify who may be vulnerable to the disease at an early stage.
Dr Anna Mantzouratou, A Visiting Fellow at Bournemouth University who supervised the research, said, "The variants we saw have been part of the human genome for a very long time, but the modern chemical environment is new, and we're beginning to understand how these interactions might influence conditions like endometriosis.
"This is an initial pilot study, but it marks an important step toward connecting the dots between our genetic makeup and the world we live in. If we can better understand how environmental exposures 'activate' or influence these biological processes, we may be able to identify risk earlier and support women long before symptoms become severe."
Amelia concluded, "I think a lot of women with endometriosis feel that they are not being listened to and nothing is being done. Showing them that we are trying to do something for them and trying to make a difference is really important for me."
