Scientists have discovered a gene which may explain why some women are infertile. Statistics show that although 90 per cent of couples who undergo IVF treatment produce embryos, only 20 per cent of those successfully implant in the womb. The discovery may eventually improve success rates in fertility treatments.
The scientists, from the Imperial College School of Medicine and Hammersmith Hospital, report that they have located a gene which seems to be linked to a susceptibility to infertility. El-Nasir Lanlani and colleagues have found that implantation of embryos in women with a defective version of the gene, called MUC 1, is less successful than in those women in whom the gene is not defective.
The study, which was published in The Lancet, compared the structure of the MUC 1 gene in two groups of women. A control group of women was used, all of whom had previously had at least two spontaneous and uneventful pregnancies. These were compared with a group of women who had a history of unexplained infertility, suspected to be as a result of implantation failure. It was discovered that part of the MUC 1 gene in the group of infertile women tended to be much smaller.
The gene produces a sticky protein which may play a part in helping embryos attach to the womb walls. When quantities of the protein are not sufficient, it may mean that embryos do not implant. This would cause a woman to be labelled infertile in the first place, but it might mean that IVF treatment is less likely to succeed.
Professor Robert Winston of the Hammersmith Hospital said that 'the discovery that the size of a single gene could influence fertility is important and it should offer a potential target for new treatment'.