A new method of genome-wide analysis of embryos for IVF
Geneticists at the Center for Infertility Treatment at New York University used a new technique developed by Complete Genomics to analyze information obtained by genome-wide DNA sequencing of two 5-day-old embryos of the same parents. This allowed them to identify mutations that were not inherited from their parents, but arose spontaneously in an egg or sperm. This approach will allow scanning the genome of embryos prepared for artificial insemination in order to identify potentially dangerous mutations.
Modern methods of preimplantation genetic diagnostics used by reproductive clinics can detect only large chromosomal abnormalities or genetic mutations transmitted to embryos fertilized in the laboratory through the genetic material of parents.
The use of single cells isolated during embryo biopsy for genome-wide sequencing, the total number of which at this stage of development usually does not exceed 10, means the need for DNA amplification, which increases the risk of errors. The technique of "reading long fragments" developed by the authors makes it possible to eliminate any mistakenly identified mutations from the results. It is based on the use of so-called DNA barcodes to match the DNA fragments of the embryo with the genomes of the mother and father. This makes it possible to eliminate more than 100,000 sequencing errors per genome, reducing the probability of error by about 100 times compared to earlier approaches.
The authors explain that each individual is a carrier of an average of 100 new mutations that can lead to the development of many diseases. Therefore, identifying these mutations and determining their origin requires the lowest possible probability of errors.
When testing the method, the analysis of one of their embryos did not reveal new mutations in the protein-coding region of the genome, whereas two potentially unfavorable coding mutations in the ZNF266 and SLC26A10 genes were identified in the genome of the second embryo of the same pair.
According to the authors, to date, the most difficult task is to develop methods for analyzing the potential impact of detected mutations on the body and decision-making tactics based on the data obtained.
They hope that in the future, genome-wide sequencing using DNA barcodes will become part of preimplantation diagnostics conducted in order to increase the likelihood of detecting disease-causing mutations and reduce the frequency of genetic diseases.
Article by Brock Peters et al. Detection and phasing of single base de novo mutations in biopsies from human in vitro fertilized embryos by advanced whole-genome sequencing is published in the journal Genome Research.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru according to Medical News Today:
IVF embryos: whole genetic code can be scanned for mutations.
13.02.2015