Answer from: Raúl Olivares, MD
Yes, you can detect trisomy 21 or Down syndromes in embryos if you do PGS on them. There are 3 types of PGS. One of them detects if the number of chromosomes is correct or not. You can also detect if there are translocations or if the chromosomes have exchanged parts of them, or you can check if there are mutations inside the chromosomes.
From these 3, the first one is so-called PGT-A because we are detecting aneuploidies, and these are all abnormalities where the embryo has extra chromosomes or lacks one chromosome. If they have an extra chromosome, that’s called a triploidy.
If the embryo only has one chromosome, it’s called Monosomy, and all these abnormalities either in excess or because the embryo lacs that chromosome can be detected by the PGS.