Scientists say the information could be used to diagnose and treat the painful womb condition that causes infertility and pain and currently has no cure.
The problem arises when cells normally found in the womb lining attach themselves to other parts of the pelvic area, causing scar tissue, pain and inflammation.
Researchers at Liverpool University have now identified that the enzyme, telomerase, could be responsible.
Telomerase is normally released by cells in the the womb during the early stages of the menstrual cycle, but in those affected by endometriosis, the enzyme is also released during the later stages when it can destroy a woman’s chances of becoming pregnant.
Dr Dharani Hapangama, who led the research, said: “Women who have endometriosis express this enzyme in both the early and late stages of the menstrual cycle which means that the cells will continue to divide and lose their ‘focus’ in supporting the establishment of a pregnancy.
“As a result, the lining of the womb may be more hostile to an early pregnancy, and the cells that are shed at this late stage in the menstrual cycle may be more ‘aggressive’ and more able to survive and implant outside the uterus, causing pain in the pelvic or abdomen area.”
The research, which was published in the journal Human Reproduction, is now expected to help scientists develop new techniques for diagnosing and treating the condition, which affects around two million British women.