Test tube baby first to get IVF defect check
Child born after parents send cells of embryos for new method to screen for abnormalities in genome to improve chances of healthy infant
The first IVF baby screened for genetic defects using a new procedure that can read every letter of the human genome has been born.
Connor Levy was born in the US after a Philadelphia couple had cells from their IVF embryos sent to specialists in Oxford, England, who checked them for gene abnormalities. The process helped their US fertility clinic select embryos with the right number of chromosomes, which have a much higher chance of producing a healthy baby.
The birth demonstrates how next-generation sequencing (NGS), which was developed to read whole genomes quickly and cheaply, is poised to transform the selection of embryos in IVF ( in vitro fertilisation clinics).
Though on this occasion scientists only looked at chromosomes - the structures that hold genes - the falling cost of whole-genome sequencing means doctors could soon read all the DNA of IVF embryos before choosing which to implant.
If doctors had a readout of a genome, they could judge the chances of the child developing certain diseases, such as cancer, heart disease or Alzheimer's.
Marybeth Scheidts, 36, and David Levy, 41, had tried another fertility treatment three times without success before they signed up for IVF at Main Line Fertility, a clinic in Pennsylvania. As part of an international study with Dagan Wells, a fertility specialist at Oxford University, the couple were offered NGS to check their IVF embryos for abnormal chromosomes, which account for half of miscarriages.
The chances of an embryo having the wrong number of chromosomes rises with the mother's age, and potentially with the father's. Most of the time, embryos with abnormal chromosomes fail to implant. Those that do are usually miscarried. The portion that survive are born with genetic disorders, such as Down's syndrome.
After treatment at the US clinic, the couple had 13 embryos to choose from. The doctors took cells from each and sent them to Oxford for screening. Tests showed that while most looked healthy, only three had the right number of chromosomes.
"It can't make embryos better… but it can guide us to the best ones," said Wells.
The doctors transferred a healthy embryo into Scheidts. The single embryo implanted, and nine months later Connor was born, on May 18. Details of the study were due to be given at the European Society of Human Reproduction and Embryology meeting in London yesterday.
"Many of the embryos produced during infertility treatments have no chance of becoming a baby because they carry lethal genetic abnormalities," Wells said. "Next generation sequencing improves our ability to detect these abnormalities and helps us identify the embryos with the best chances of producing a viable pregnancy."
Doctors can already screen embryos for abnormal chromosomes using a technique called Array CGH, but that adds more than £2,000 (HK$23,000) to the cost of IVF.
"The new method should allow costs to be reduced by several hundred pounds, potentially bringing the benefits of chromosome screening within the reach of a far greater number of patients," Wells said.
Additional reporting by Agence France-Presse