Date/Time
Date(s) - 01/03/2017
11.00 - 12.00
Location
Universitat de Vic. Campus Torre dels Frares
Category(ies)
Location: Ts121
Santiago Munne, PhD
Chief Scientific Officer, CooperGenomics
Preimplantation Genetic Diagnosis of human embryos consist of creating embryos in vitro, sampling one or few cells per embryo, and analyzing the embryos for chromosome or gene detects. The sampling of the embryo can be performed at day 3 or 5 of embryo development, but DNA from the embryo has been recently analyzed from the media were the embryo was cultured. A variety of techniques can be used to analyze all chromosomes, such as qPCR, array CGH or next Generation Sequencing (NGS). NGS has a higher dynamic range allowing for the detection of mosaicism, or 1/5 biopsied cells being abnormal.
More than 100,000 patients have been treated with PGS for the purpose of increasing the probability of achieving a healthy pregnancy. A women 25 years old will produce 30% abnormal embryos but increases with advancing maternal age to 80% at age 42. Maternal age is the major cause of embryo loss. After PGS and transferring normal embryos, they implant equally well at any age, and miscarriage rates are significantly reduced.
For couples planning a pregnancy Carrier Screening of >300 severe gene defects can now be performed by NGS or genotyping (SNP arrays). About 45% of individuals will be carriers of one of these diseases while 2-3% of couples will be both carriers of the same gene defect and therefore at risk of producing affected babies. These couples can be helped by PGD in which the gene defect is screened and only normal embryos are transferred. The technique used for that form of PGD is Karyomapping.
Finally, some abnormalities are no inherited not related to maternal age. With increasing paternal age, there is an increase in de novo SNP and CNV mutations, which are probably related to the epidemic of Autism and other mental diseases. New methods of DNA amplification, and sophisticated bioinformatics are needed to screen for de novo mutations in human embryos.