First pregnancy in Europe through IVF method that screens out defective embryos
Europe sees its first pregnancy from cutting-edge genetic selection technique
Doctors in London have reported the first pregnancy in Europe from a new IVF procedure that checks embryos for genetic disorders before they are implanted.
The technique allows doctors to select embryos that are free of dangerous mutations carried by one or both parents even if the precise nature of the genetic defect is unknown.
Fertility specialists at Britain's Centre for Reproductive and Genetic Health said the anonymous couple, who had a high risk of passing on a lethal disease to their children, were 11 weeks into the pregnancy.
Common embryo testing procedures require months of laboratory work, but the latest tool, known as karyomapping, can be completed within two weeks, meaning a couple can undergo tests without breaking from their IVF treatment cycle.
Paul Serhal, medical director of the centre, said that the technique, which will be available on the UK's publicly funded healthcare system, the National Health Service (NHS), was likely to replace more traditional ways of testing embryos because it was faster, more powerful, and no more expensive. A second couple are 10 weeks into a pregnancy after receiving the same treatment at the clinic.
"Parents at risk of passing on a genetic disorder are faced with heartbreaking implications of potentially creating a life with an inherited illness. The breakthrough we have achieved means that parents affected may be able to pursue treatment confident that their condition wouldn't be handed down," Serhal said.
The couple have standard IVF treatment to create a set of embryos which are then biopsied. Usually, a few cells are taken when the embryo is a ball of 100 or so cells, though single cells can be plucked from younger, three-day-old embryos.
To perform the karyomapping, doctors first obtain DNA from cheek swabs of the parents and a family member affected by the disorder. The gene sequences are then compared and used to work up a genetic fingerprint for the mutation that causes the disease.
Armed with the genetic fingerprint, doctors can check the cells removed from the embryos and work out which will be affected or not by the disorder, or carriers that could pass the disease on. The test also checks that embryos have the right number of chromosomes, a common cause of miscarriage and developmental disorders, such as Down's syndrome.
"In more than two decades of working this field, this is the single biggest technological leap I have seen. Karyomapping is already making a significant difference to patients," said Dagan Wells at Reprogenetics UK, an Oxford-based company that tested the embryos.