Queensland scientists lead international study discovering genes behind endometriosis

A team of international scientists headed by the Queensland Institute of Medical Research (QIMR) has made a major genetic discovery in unlocking some of the mysteries of endometriosis.

Endometriosis, which causes up to 50% of female infertility, is a gynaecological condition where endometrium-tissue (normally found lining the uterus) actually grows outside the uterus and on pelvic organs. The condition disables women in their reproductive years and causes pelvic pain, menstrual disturbance, scarring and tissue damage, and fertility problems.

It has long been thought to have a familial or hereditary basis and the QIMR study, which has been going for more than 10 years and was co-founded with Brisbane gynaecologist Dr Daniel O’Connor, revealed chromosome 10 as containing the area in which the most significant genes for endometriosis are located.

“Now that we have pin-pointed the chromosomal area, we can start to examine which genes on the chromosome are actually responsible for this disease, which does run in families and has a significant impact on health and reproduction,” said Chief Investigator, Dr Sue Treloar from QIMR’s Genetic Epidemiology Group.

The major study, which was published in the American Journal of Human Genetics, achieved one of the largest collection of sibling pairs (sisters in this case) for a complex disease that has ever been achieved anywhere in the world. In total, around 4,000 women with surgically confirmed endometriosis have participated in the study.

“Apart from taking DNA from the women with endometriosis, we also included their parents and other family members – bringing the total to around 10,000 people across Australia. The extracted DNA samples are now stored in our freezers, and our team led by Dr Grant Montgomery is using them for different tests of association with endometriosis,” said Dr Treloar.

To complement this study, QIMR scientists will also participate in a major study to see if there is a correlation between endometriosis and breast density. Endometriosis is a hormonally-influenced condition and women often take hormonal type medications for endometriosis. A Scandinavian study some years ago showed a small increase in risk of breast cancer in women diagnosed with endometriosis It is also known that breast density is a risk factor for breast cancer.

The new project will investigate whether breast density differs in women diagnosed with endometriosis compared with other women, and whether breast density is influenced by genes.