title: Counselling considerations for chromosomal mosaicism detected by preimplantation genetic screening.
abstract: The evolution of preimplantation genetic screening (PGS) for aneuploidy to blastocyst biopsy and more sensitive 24-chromosome screening techniques has resulted in a new diagnostic category of PGS results: those classified as mosaic. This diagnosis presents significant challenges for clinicians in developing policies regarding transfer and storage of such embryos, as well as in providing genetic counselling for patients prior to and following PGS. Given the high frequency of mosaic PGS results and the wide range of possible associated outcomes, there is an urgent need to understand how to appropriately counsel patients regarding such embryos. This is the first commentary to thoroughly address pre- and post-test genetic counselling recommendations, as well as considerations regarding prenatal screening and diagnosis. Current data on mosaic PGS results are summarized along with embryo selection considerations and potential outcomes of embryos diagnosed as mosaic.
authors.affiliation: New York University Fertility Center, New York University Langone Medical Center, 660 First Avenue, New York, NY 10016, USA.
authors.forename: Andria G
authors.initials: AG
authors.lastname: Besser
authors.affiliation: Oregon Reproductive Medicine, 808 SW 15th Avenue, Portland, OR 97205, USA. Electronic address: emounts@oregonreproductivemedicine.com.
authors.forename: Emily L
authors.initials: EL
authors.lastname: Mounts
mesh_terms: D004624:Embryo Transfer / Q000941:ethics; D005260:Female; D005817:Genetic Counseling / Q000379:methods*; D006801:Humans; D009030:Mosaicism / Q000196:embryology*; D011247:Pregnancy; D019836:Preimplantation Diagnosis / Q000379:methods* / Q000639:trends
keywords: Genetic counselling; Mosaicism; Next-generation sequencing; Preimplantation genetic screening; Prenatal diagnosis