The Outcomes Of Embryos For The Carriers Of Single Gene Disorders By Preimplantation Genetic Testing And The Necessity Of Simultaneous Aneuploidy Screening

Chapter 1:The outcomes of embryos for the carriers of single gene disorders by preimplantation genetic testing and the necessity of simultaneous aneuploidy screeningPreface Single gene disorders refer to diseases or pathological traits controlled by a single pair of alleles.With the improvements of preimplantation genetic testing for monogenetic diseases(PGT-M),increasing couples who are the cariers of single gene disorders are benefiting from it.Nevertheless,some non-pathogenic embryos obtained after PGT-M for carriers of single gene disorders may be accompanied with aneuploidy,which may result to adverse pregnancy outcomes such as miscarriage and the risk of birth defects.Thanks to preimplantation genetic testing for aneupolid(PGT-A),which is a diagnostic technique for the purpose of transferring only euploid embryos into the uterus after the preimplantation genetic screening for aneuploidy of embryos.Purpose The main aim of the article is to identify the necessity of simultaneous PGT-A for carriers of single gene disorders who are under PGT-M therapy already.Method This is a retrospective study which reviewed 119 patients who with a family history of single gene disorders(SGD)accepted PGT-A along with PGT-M.And analyze the PGT-A results of non-pathogenic embryos(including carrier embryos)obtained by PGT-M.Result Among 326 non-pathogenic embryos(including carrier embryos),123 embryos(37.73%)were abnormal after PGT-A.and the risk of abnormality occurs in all 23 chromosomes,particularly16,22 and sex chromosome with a higher rate.There was a significant difference in embryonic aneuploidy rate between subgroups<35 years old and>35 years old(P=0.002).Though no statistical significance was found in the rate of multiple chromosomal abnormality embryo for subgroups<35 years old and>35 years old(P=0.271),The women with advanced age have a higher incidence of multiple chromosomal abnormalities.To analyze the pregnancy outcome,the biochemical pregnancy rate and clinical pregnancy rate was as high as 74.51%and 72.55%,the live birth rate was 67.65%.Conclusion:1.PGT-A plays an important role in selecting embryos among the carriers of single gene disorders in PGT-M cycles already.It helps to find aneuploid embryos so as to reduce the rate of implantation failure,abortion and other adverse pregnancy outcome.2.Every chromosome has the potential to be abnormal after PGT-A cycles.For women of advanced age,The rate of aneuploidy embryo and multiple chromosomal abnormalities is higher.Chapter 2:The outcomes for the carriers of single gene disorders by preimplantation genetic testingPreface Faced with all kinds of problems,the application of PGT-M was still limited.Though,the genetic characteristic of single gene disease accords with Mendelian heredity law in theory,What's the outcome for patients of single gene disorders by preimplantation genetic diagnosis?Is it consistent with the theoretical value?Purpose To analyse the outcome of embryos for carriers of single gene disorders by preimplantation genetic testing and the coincidence the results of amniocentesis and PGT-M for pathogenic gene.Method This is a retrospective study which reviewed 124 patients who asked for genetic counseling in the Reproductive hospital affiliated to Shandong university due to family history of single gene disorders and had experienced PGT-M from October 2013 to March 2018.And analyse the actual outcome of embryos and the results of amniocentesis.Result There is no difference in the results of the actual and theoretical outcome for Polycystic kidney(AD),Spinal muscular atrophy(AR),congenital deafness(AR),Methylmalonate(AR),Hemophilia(XR)and Duchenne muscular dystrophy(XR).It's completely consistent for the results of amniocentesis and PGT-M for pathogenic gene in 32 fetus.Conclusion1.The outcome for carriers of single gene disorders by preimplantation genetic diagnosis conforms to Mendelian heredity law,which provides actual guidance to genetic counselling.2.It's completely consistent for the results of amniocentesis and PGT-M for pathogenic gene,which proves the reliability of PGT-M.