New Insights into PCOS Inheritance
Researchers might be getting closer to explaining why polycystic ovary syndrome (PCOS) often appears in families.
During the 41st Annual Meeting of the European Society of Human Reproduction and Embryology in Paris on July 1, scientists revealed that “disruptions” in the activation of genes could heighten the risk of developing PCOS. These “epigenetic” changes modify gene function without altering the DNA sequence itself, and they might also be hereditary.
This finding opens up potential pathways for preventing PCOS.
For instance, if someone is going through in vitro fertilization (IVF), “these harmful [epigenetic] markers might be identified in embryos and altered before they’re implanted, potentially stopping PCOS from being inherited,” said Dr. Sherry Ross, a board-certified OB/GYN at Providence Saint John’s Health Center in Santa Monica, California.
Yet, she pointed out that “more research is needed on human embryos to determine if this is a safe and practical approach.”
Grasping PCOS Inheritance
PCOS impacts 6% to 13% of women of reproductive age, according to the World Health Organization (WHO). Alarmingly, up to 70% of cases go undiagnosed globally. Common symptoms include ovarian cysts, weight gain, hair thinning or balding, excessive body hair, acne, fertility issues, and irregular or heavy menstrual cycles.
Along with these often challenging symptoms, individuals with PCOS face heightened risks for a range of health issues, including high blood pressure, type 2 diabetes, and endometrial cancer, according to the WHO.
PCOS has a strong genetic basis, according to Dr. Sydney Chang, medical director at CCRM Fertility of Austin.
In a study of twins, researchers found that identical twins, who share almost all their DNA, showed a higher likelihood of both having PCOS compared to fraternal twins, who share about half. This suggests that much of the risk of developing PCOS is inherited, Chang noted.
It’s estimated that 20% to 40% of individuals with PCOS have a mother or sister with the same condition, yet the precise inheritance pattern remains somewhat unclear, which is where the new research shines a light.
The study, led by Dr. Qianshu Zhu from Chongqing Medical University in China, included around 230 women undergoing IVF—133 with PCOS and 95 without. The research team examined unfertilized eggs and early embryos, searching for epigenetic markers affecting gene activity.
They found considerable disruptions in several significant genes in the eggs and embryos of those with PCOS compared to those without the condition. These affected genes participated in metabolic processes and DNA activation in early embryos, and certain genomic regions had irregularities as well.
Zhu and his team noted unusual patterns in recognized epigenetic markers controlling gene function. Interestingly, about half of the abnormal signatures observed in three-day-old embryos were already present in the egg cells, indicating that epigenetic signals from the mother might be affecting the embryo from the outset.
Understanding these mechanisms could lead to new ways to prevent PCOS. The authors propose that embryos made through IVF might be modified to adjust their epigenetic markers, thus reducing the risk of passing on PCOS. This could also enhance embryo selection methods during IVF.
However, Zhu cautioned that this research involves lab-created embryos and doesn’t directly demonstrate how these epigenetic markers could impact actual children. His team is planning mouse studies to explore potential effects further.
“What’s exciting about this new study is that it supports a genetic link between PCOS in families,” Ross remarked, “and it sheds light on early diagnosis and potential interventions to stop PCOS from being passed through generations.”
