A recent discovery by researchers at Tsinghua University in China has been identified as a catalyst for premature ovarian insufficiency, a cause of infertility. The researchers revealed that a gene, named ‘Eif4enif1’, can become subject to alteration, impacting the release of the egg from the ovary as well as the mitochondria within the egg cells, leading to fertility issues.
The groundbreaking research has been published in the journal Development, and provides more insight into premature ovarian insufficiency.
What is premature ovarian insufficiency?
Premature ovarian insufficiency (POI), also known as premature ovarian failure or early menopause, is characterised by the loss of function in the ovaries before the age of 40. When you have POI, your ovaries stop producing the normal amount of oestrogen required to release an egg, therefore, the most common and obvious symptom of this condition is the cessation of periods. This also, for most women with POI, greatly reduces the chance of conception or eliminates it altogether, though some women may still retain intermittent ovarian function.
Those with POI are likely to experience symptoms associated with menopause, including hot flushes, fatigue, brain fog, mood swings and loss of libido. Some women may also suffer from thinning hair, vaginal dryness and joint pain.
POI is caused by genetic conditions such as Turner syndrome; surgery that impacts the ovaries; cancer treatment; certain infections such as malaria; and autoimmune disease. POI can be diagnosed with a blood test, which measures the patient’s levels of a hormone called follicle-stimulating hormone (FSH). In those with POI, the level of this hormone is higher than normal. According to the British Menopause Society, it is estimated that 1% of women have POI.
The treatment for POI is Hormone Replacement Therapy (HRT). This involves replacing the hormones that the body is not producing. HRT provides symptom relief for those with POI, but does not cure it. Many women continue receiving HRT until they reach the typical age of menopause.
If you have received a POI diagnosis, in some cases it is still possible to have a baby. As mentioned, some women still have intermittent ovarian function despite having POI. In addition, it may be possible to use your own eggs in IVF, or use eggs from an egg donor. If you are based in the city, a fertility clinic in London will be able to advise you on your options and the best course of action for you.
How does gene alteration lead to premature ovarian insufficiency?
Researchers determined that modification to the gene Eif4enif1 leads to complications in egg cells, which impedes the release of eggs from the ovaries. They studied a family with POI, finding that all members exhibited changes to the Eif4enif1 gene, and recreated the genetic alteration in mice, discovering that the mice presented a 40% reduction in average number of total follicles (sacs in the ovaries that contain a developing egg).
These mice produced offspring, and it was found that the number of offspring reduced by a third per litter. It was also found that half of the litter’s fertilised eggs did not pass beyond the early developmental stages during in vitro fertilisation (IVF).
After microscopic analysis of the egg cells, the researchers found abnormal clustering of the mitochondria. Mitochondria are organelles (functional subunits of cells), and they’re found in every cell in our body apart from red blood cells. Their function is to provide each cell with energy that is converted from the food we eat. Egg cells need energy from mitochondria in order to successfully complete fertilisation; without them, fertilisation is impeded and conception does not occur.
Therefore, even if egg release has occurred, the egg would not have the energy required for reproduction.
The next phase of research would be to carry out similar investigations with human eggs. Although it is too early to predict what may come of this research, there is potential that it could lead to gene-modifying treatments that could correct the issue, and in the future improve chances of conception for those with the altered gene.
Struggling with infertility?
Around one in seven couples (NHS) have difficulty conceiving. This can be a frustrating process, with a great impact on your emotional and mental health. If you have been trying to conceive for over a year with no positive results, it may be time to see a fertility specialist who will be able to investigate your issues and recommend a course of action to support you in your journey towards parenthood.