SpainFertility

Veterinary researchers from University of Pennsylvania, USA, have identified a gene, called TEX11, which is on the X chromosome, that causes sterility in male mice and reduces female fecundity when disrupted. This study is the first that searches genetic causes of infertility linking a particular sex chromosome to sterility.

The TEX11 is also found on the human X chromosome. Since the disruption of this gene causes azoospermia in mice, mutations in this gene in humans may be a genetic cause of infertility in men. Men have only one X chromosome, inherited from their mother and therefore only one copy of the TEX11 gene. That is why any mutation of the gene can lead to sterility: this means that genetic mutation causing a son´s infertility could be passed from his mother. The team of researchers believe that a screening of the TEX11 gene could provide a pre-birth diagnosis for infertility in men.

The study lead by these researchers reports the first meiosis-specific factor ever found on the X chromosome. Meiosis is the process of cell division that produces gametes in both sexes. During this process, exchange of genetic material between mother and father takes place, and that is why any defect in meiosis is a leading cause of infertility and birth defects.

During the initial stages of meiosis, the TEX11 gene has a significant role that, when disrupted, causes homologous chromosomes to fail to pair together during meiosis. These failures can lead to elimination of spermatocytes at later stages in the genetic recombination process and, eventually, to male infertility.

Researchers hypothesize that because TEX11 interacts with SYCP2, an integral component of the protein complex that mediates synapsis during meiosis, TEX11 promotes both synapsis and genetic recombination and may provide a physical link between these two meiotic processes.

‘Spain becomes the destination of choice for fertility tourists from Britain’ | “Spain has become the destination of choice for childless, infertile British couples driven to seek help abroad by a dramatic fall in the number of people prepared to donate eggs or sperm at home. Fertility clinics in Spain have told the Guardian that numbers have increased by between 50% and 100% since Britain passed a law in April last year that gave children the right to know the identity of their biological parents.

Some British donors have even offered to travel to Spain, where anonymity is guaranteed, to give eggs that could later be used by infertile women.

Spanish clinics have begun to advertise among eastern European immigrant communities for potential egg donors to help meet the leap in demand from British fertility tourists.

One clinic has distributed ads in Russian and Polish as they seek tall, fair-skinned or fair-haired European donors who look similar to their clients. They show a young woman with a pierced belly-button and a tattoo peeking out from above the belt of her jeans. “You are young and you have thousands of them,” they say. “Become an egg donor.”

“The idea is to increase the number of donors who are fair Caucasians,” said Dr Raul Olivares of the Instituto Marques clinic in Barcelona. “The flow of British clients is increasing all the time. We are OK for the moment, but eventually we might run out.” Two other Spanish clinics, in Barcelona and Valencia, told the Guardian similar stories.”

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“”We already had some British patients, but a lot more have come since donors lost their anonymity,” said David Marina of the Cefer clinic in Barcelona. “Patients are stressed and anguished by the wait.”

Dr Marina said that Spanish law explicitly protects a donor’s anonymity. “Donors do not want to be parents, they want to be donors,” he said. “If you tell them that in 18 years a young person will turn up and treat them like a parent, it puts them off.” The law is backed by the country’s highest court, the constitutional tribunal. “In Spain, donors have no rights and no obligations,” he said. “Most couples here do not actually inform the child that there has been a donor involved.””

The Pacific Fertility Center (PFC) located in San Francisco, California, has developed an oocyte vitrification program. This method allows preservation of eggs, which signifies an important breakthough in fertility studies.

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 The selection of eggs has been improved largely by a new method developed by a research team supervised by Marc-Andre Sirard, scientist of Université Laval, in France. Sirard and his team identified genetic markers that allow the selection of eggs with better chance of leading to pregnancy after in vitro fertilization (IVF). Thanks to this, the rate of success for single embryo transfer could be increased, and also the risk of multiple pregnancies diminished.

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