PGD (Pre Implantation Geneticdiagnosis) is used to check the embryos abnormalities in chromosomes number. PGD is the genetic profiling of embryo prior to implantation?
The term preimplantation genetic screening (PGS) refer to the set of techniques for testing whether embryo (obtained through IVF / ICSI) have abnormal chromosome number. In other word, it tests if embryo is aneuploid or not. PGD is also called aneuploidy screening. PGS was renamed preimplantation genetic diagnosis for aneuploidy (PGD-A) by preimplantation genetic international society.
The PGD allows studying the DNA of eggs or embryo to those that carry certain mutation for genetic disorder. It is useful when there is previous chromosomal or genetic disorder in the family and within the context of in vitro fertilization program.
The procedure may also be called preimplantation genetic profiling to adapt to the fact that they are sometime used on oocyte or embryo prior to implantation for other reason than diagnosis or screening.
PGD provide a method of prenatal sex determination even before implantation, and may therefore be termed preimplantation sex discernment. In the case of families at risk for x – linked diseases, patients are provided with a single PGD assay for gender identification. The selection of female embryo offspring is used in order to prevent the transition of X- linked Mendelian recessive diseases. Such X-linked Mendelian disease includes Duchene muscular dystrophy (DMD).