Experts discuss overlap between genetics and infertility

Experts in clinical genetics and assisted reproduction met last week to discuss issues that affect both areas of medicine, such as embryo testing, genetic causes of infertility, possible long term effects of assisted reproduction techniques, counselling concerns and European regulations. The workshop, held at the Institute for Prospective Technological Studies in Seville, Spain, was jointly organised by members of the European Society of Human Genetics (ESHG) and the European Society of Human Reproduction and Embryology (ESHRE).

The meeting highlighted the fact that an increasing number of genetic causes of infertility are being identified, but that patients are not routinely tested for all of these. The diagnosis of conditions such as congenital bilateral absence of the vas deferens (CABVD) - male infertility caused by alterations in the same gene involved in the inherited lung condition cystic fibrosis - should be accompanied by genetic counselling, said the participants. In contrast, most felt that the increasingly used PGS (preimplantation genetic screening) technique, which involves checking an embryo's chromosomes to select those most likely to implant, does not require routine genetic counselling.

PGD experts urged infertility clinics, when reporting results, to distinguish between PGS and PGD, in which an embryo is tested for a specific genetic alteration. Without this distinction, they said, it will be difficult to collect European and international data on the use and outcomes of the two techniques.

All participants agreed on the need for more long-term follow up studies to monitor the long term health effects of both preimplantation testing and IVF in general. Some groups have published evidence suggesting a link between IVF techniques and an increased risk of some genetic conditions, but large studies will be needed to investigate these claims, since these disorders are very rare.

Another area discussed at the meeting was the extent to which egg and sperm donors should be checked for possible medical problems. Although screening for infectious diseases such as HIV (human immunodeficiency virus) is routinely carried out, clinics across Europe vary in the number of chromosome and genetic tests carried out on potential donors. A balance needs to be struck between protecting recipients and the costs of genetic testing, as well as respecting a donor's right not to know such information, said the experts.

Regulations governing the use of donated eggs and sperm vary across Europe, one reason for the rise in cross border reproductive care, often called 'reproductive tourism' - a term felt by many participants to have negative connotations. The experts agreed that this trend is set to continue, and that European guidelines governing technical standards, safety and patient care are required. In particular, patients should be told of the potential risks associated with assisted reproduction techniques still considered experimental by many countries, such as cytoplasmic transfer. Recommendations based on the discussions will appear shortly on both the ESHG and ESHRE websites, and will be published later this year.