Hope for women with incurable ovaries: scientists discover the gene that causes it

New research suggests that a male gene that triggers abnormal testosterone levels in women could be the leading cause of infertility.

A study of the causes of polycystic ovarian syndrome (PCOS), which affects one in 10 women of childbearing age, revealed that DNA containing high levels of testosterone plays a key role in the disease.

PCOS, the leading cause of infertility in women and type 2 diabetes, affects one in 10 women of childbearing age.

The study, conducted by scientists from Chicago and New York, is the first of its kind to use family genetic analysis to study the causes of PCOS.

The disease is also linked to weight gain, excessive hair growth and acne in women.

Research has revealed that a gene involved in the production of male hormones called DENND1A plays a major role in the development of PCOS.

The discovery could now lead to new methods of treatment.

Lead author of the study, Dr. Andrea Dunaif, of the Icahn School of Medicine at Mount Sinai, New York, said: "PCOS is a major cause of female infertility and is associated with other serious health problems.

"Our results provide important new information on the mechanisms by which genetic variation causes PCOS.

"The rare genetic variants we found are perhaps much better at predicting disease than common variants.

"The targeting pathways regulated by this gene could lead to new treatments for the disease."

Dr. Dunaif explored the genetic basis of PCOS.

She and her team analyzed the entire genome sequencing of the DNA of members of 62 families of women with PCOS.

Families who volunteered to participate in the study included both parents and one or more childbearing girls with PCOS, as well as unaffected girls.

The genes were analyzed and the team discovered which genes contained variants that could damage women's ovaries.

About half of the families carried rare genetic variants of the male gene, DENND1A, in their reproductive and metabolic hormone levels.

The gene plays an important role in the production of testosterone in the ovaries – an essential hormonal imbalance observed in women with PCOS.

Dr. Geoffrey Hayes, co-author, associate professor at Northwestern University, added, "After sequencing all the genomes of many families affected by the disease, this allowed us to study the link between some rare genetic variants and PCOS.

"We hope our findings will help to uncover some of the hereditary mechanisms involved and, ultimately, to learn more about the molecular factors of the disease."

The research began at the Feinberg School of Medicine at Northwestern University in Chicago and was completed at the Icahn School of Medicine, Mount Sinai, New York.

The results were published in the Journal of Clinical Endocrinology and Metabolism.