31 May 2011
ByAppeared in BioNews 609
Multiple genetic tests have been performed on a single embryo for almost the first time, according to US researchers. The researchers from John Hopkins School of Medicine say their technique for making copies of an embryo's DNA can improve IVF success rates.
In a study published in April's Fertility and Sterility, they successfully tested embryos from a woman undergoing IVF treatment for both aneuploidy and the single gene disorder GM1 gangliosidosis. She gave birth to a healthy child.
Dr Paul Brezina, a clinical fellow in obstetrics and gynecology, who carried out the research said: 'We were able to amplify the genomic DNA accurately to the point where both single-gene testing and aneuploidy screening could be done. Up till now it has only been one or the other'.
Previously the number of different genetic tests that could be performed on an embryo during IVF was limited by the small amount of DNA that can be taken from an embryo.
The new 'modified multiple displacement amplification' technique replicates a tiny amount of DNA extracted from a single cell of a three-day old embryo so it can be tested for several disorders. Unaffected embryos can be used for the rest of the IVF treatment.
Since the study was published online in December 2010, this combination of tests has been offered to seven more women by study co-author Dr William Kearns at the Shady Grove Center for Preimplantation Genetics in Rockville, USA. Five women have so far become pregnant with the technique.
Speaking about one of the women, Dr Kearns said: 'She is a 39-year-old woman who is a carrier for Fragile X syndrome (a genetic disease that causes mental disabilities) and had two first trimester miscarriages. We did the same methodology on her and now she is pregnant. It is spectacular'.