Preimplantation genetic diagnosis for Down syndrome pregnancy

Objective: To evaluate the effect of preimplantation genetic diagnosis (PGD) conducted for women who had Down syndrome pregnancy previously. Methods: Trisomy 21 was diagnosed by using fluorescence in site hybridization (FISH) before embryo transfer in two women who had Down syndrome pregnancies. Each received one or two PGD cycles respectively. Results: Case 1: one PGD cycle was conducted, two oocytes were fertilized and biopsied. One embryo is of trisomy 21 and the other of monosomy 21. No embryo was transferred. Case 2: two PGD cycles were conducted, in total, sixteen oocytes were fertilized and biopsied. Four embryos were tested to be normal, six of trisomy 21, and one of monosomy 21. Five had no signal. Four normal embryos were transferred but no pregnancy resulted. Conclusion: For couples who had pregnancies with Down syndrome pre-viously, PGD can be considered, and has been shown to be an effective strategy.

Establishment of a Simple and Useful Way for Preimplantation Genetic Diagnosis of Chromosomal Diseases

In order to establish a simple and useful way for preimplantation genetic diagnosis (PGD) of chromosomal diseases in general IVF laboratory, the methods that are most commonly used in the embryo biopsy, fixation of blastomere and fluorescence in situ hybridization were compared. The three aspects of PGD were analyzed respectively. There was no significant difference in further de- velopment capacity of embryos between mechanical (79.7%) and chemical biopsy group (78.6%) (P>0.05). In this study, more cells were successfully fixed with the Tween/HCL method (93.8%) than with the methanol/acetic acid method (80.5%, P<0.05). There was no significant difference in cyto- plasm remains between methanol/acetic acid method and Tween/HCL method (P>0.05). The hy- bridization efficiency of fluorescence in situ hybridization was 89.5% in successive denaturation method and 90.9% in codenaturation method with the difference being not significant (P>0.05). In conclusion, the mechanical or chemical method, Tween/HCL fixation method and codenaturation fluorescence in situ hybridization method can constitute a simple and useful way for PGD of chro- mosomal diseases.

Atelosteogenesis Type 2/Diastrophic Dysplasia Phenotypic Spectrum: From Prenatal to Preimplantation Genetic Diagnosis

Atelosteogenesis type II (AO2) and diastrophic dysplasia (DTD) are two recessively inherited, severe skeletal dysplasias caused by mutations in the SLC26A2 gene. AO2 is an invariably lethal condition, while DTD patients may reach adult life, although both diseases have overlapping diagnostic features. Here we report a patient with an intermediate phenotype between AO2 and DTD and present the successful application of preimplantation genetic diagnosis (PGD) in this situation. Sequencing of SLC26A2 alleles in the infant identified two compound heterozygous mutations, p.Arg178Ter and p.Arg279Trp, of paternal and maternal origin, respectively. At request from the parents, PGD was developed by haplotype mapping of parental SLC26A2 alleles in eleven five-day embryos. Transference to the mother was attempted twice, finally resulting in pregnancy and delivery of a healthy baby. This exemplifies the utility of PGD for inherited lethal conditions with a significant risk of recurrence, and highlights the importance of accurate diagnosis of skeletal dysplasias with prenatal manifestation.

Clinical applications of MARSALA for preimplantation genetic diagnosis of spinal muscular atrophy

Conventional PCR methods combined with linkage analysis based on short tandem repeats （STRs） or Karyomapping with single nucleotide polymorphism （SNP） arrays, have been applied to preimplantation genetic diagnosis （PGD） for spinal muscular atrophy （SMA）, an autosome recessive disorder. However, it has limitations in SMA diagnosis by Karyomapping, and these methods are unable to distinguish wild- type embryos with carriers effectively. Mutated allele revealed by sequencing with aneuploidy and linkage analyses （MARSALA） is a new method allowing embryo selection by a one-step next-generation sequencing （NGS） procedure, which has been applied in PGD for both autosome dominant and X-linked diseases in our group previously. In this study, we carried out PGD based on MARSALA for two carrier families with SMA affected children. As a result, one of the couples has given birth to a healthy baby free of mutations in SMA-causing gene. It is the first time that MARSALA was applied to PGD for SMA, and we can distinguish the embryos with heterozygous deletion （carriers） from the wild-type （normal） ones accurately through this NGS-based method. In addition, direct mutation detection allows us to identify the affected embryos （homozygous deletion）, which can be regarded as probands for linkage analysis, in case that the affected family member is absent, In the future, the NGS-based MARSALA method is expected to be used in PGD for all monogenetic disorders with known pathogenic gene mutation.

Review:Whole genome amplification in preimplantation genetic diagnosis

Preimplantation genetic diagnosis (PGD) refers to a procedure for genetically analyzing embryos prior to implantation,improving the chance of conception for patients at high risk of transmitting specific inherited disorders.This method has been widely used for a large number of genetic disorders since the first successful application in the early 1990s.Polymerase chain reaction (PCR) and fluorescent in situ hybridization (FISH) are the two main methods in PGD,but there are some inevitable shortcomings limiting the scope of genetic diagnosis.Fortunately,different whole genome amplification (WGA) techniques have been developed to overcome these problems.Sufficient DNA can be amplified and multiple tasks which need abundant DNA can be performed.Moreover,WGA products can be analyzed as a template for multi-loci and multi-gene during the subsequent DNA analysis.In this review,we will focus on the currently available WGA techniques and their applications,as well as the new technical trends from WGA products.

Advances in preimplantation genetic diagnosis/screening

Preimplantation genetic diagnosis(PGD)gives couples who have a high risk of transmitting genetic disorders to their baby the chance to have a healthy offspring through embryo genetic analysis and selection.Preimplantation genetic screening(PGS)is an effective method to select euploid embryos that may prevent repeated implantation failure or miscarriage.However,how and to whom PGS should be provided is a controversial topic.The first successful case of PGD of a human being was reported in 1990,and there have been tremendous improvements in this technology since then.Both embryo biopsy and genetic technologies have been improved dramatically,which increase the accuracy and expand the indications of PGD/PGS.

A New Next-Generation Sequencing-Based Assay for Concurrent Preimplantation Genetic Diagnosis of Charcot-Marie-Tooth Disease Type 1A and Aneuploidy Screening

Charcot-Marie-Tooth （CMT） disease is the most common hereditary neuropathy, with a population prevalence of 1 in 2500. CMT disease type 1A （CMT1A）, accounting for ~70% of CMT1 cases and ~ 50% of all CMT cases, is transmitted in an autosomal dominant manner. CMT1A maps to chromo- some 17pl 1.2 and is caused, in the majority of cases, by a 1.4- Mb tandem duplication that includes the peripheral myelin protein22 （PMP22） gene （Li et al., 2013）. The disease usually presents in the first 20 years of age, causing difficulty in walking or running, distal symmetrical muscle weakness and wasting, and sensory loss （van Paassen et al., 2014）.

Preimplantation genetic diagnosis of hereditary hearing loss:a narrative review

Preimplantation genetic diagnosis(PGD)uses molecular biological techniques to genetically diagnose embryos beforein vitro fertilization.The information obtained through PGD can help clinicians select healthy embryos for implantation,prevent the transmission of inherited diseases and help affected families have healthy children.This paper reviews the development of PGD technology,the history of its application to hereditary hearing loss,and the general process of how PGD is applied to screen for hereditary hearing loss.The aim of this review is to demonstrate the reliability of PGD in the primary prevention of hereditary hearing loss,assist clinicians in counseling patients at risk of transmitting an inherited disease,and explore the journey from PGD toin vitro fertilization.Given that the application of PGD technology to hereditary hearing loss varies in different countries and regions,there is still a long way to go before PGD is routinely applied for the primary prevention of hereditary hearing loss.

preimplantation genetics diagnosis译为“植入前遗传诊断”为妥

1.implantation按1993年《全国自然科学名词审定委员会公布、胚胎学名》第126页,审定“implantation”译为“植入”(胚泡进入子宫内膜的过程)编号为02.078。 2.人民卫生出版社出版的《英汉医学词汇》第706页和《汉英医学词汇》均将implantation译为“植入”(胚泡在子宫内)。

Identification of embryonic chromosomal abnormality using FISH-based preimplantaion genetic diagnosis

Objective: Embryonic chromosomal abnormality is one of the main reasons for in vitro fertilization (IVF) failure. This study aimed at evaluating the value of Fluorescence in-situ Hybridization (FISH)-based Preimplantation Genetic Diagnosis (PGD) in screening for embryonic chromosomal abnormality to increase the successful rate of IVF. Method: Ten couples, four with high risk of chromosomal abnormality and six infertile couples, underwent FISH-based PGD during IVF procedure. At day 3, one or two blastomeres were aspirated from each embryo. Biopsied blastomeres were examined using FISH analysis to screen out embryos with chromosomal abnormalities. At day 4, embryos without detectable chromosomal abnormality were transferred to the mother bodies as in regular IVF. Results: Among 54 embryos screened using FISH-based PGD, 30 embryos were detected to have chromosomal abnormalities. The 24 healthy embryos were implanted, resulting in four clinical pregnancies, two of which led to successful normal birth of two healthy babies; one to ongoing pregnancy during the writing of this article; and one to ectopic pregnancy. Conclusion: FISH-based PGD is an effective method for detecting embryonic chromosomal abnormality, which is one of the common causes of spontaneous miscarriages and chromosomally unbalanced offsprings.

Chromosomal disorders and male infertility

Infertility in humans is surprisingly common occurring in approximately 15% of the population wishing to start a family. Despite this, the molecular and genetic factors underlying the cause of infertility remain largely undiscovered. Nevertheless, more and more genetic factors associated with infertility are being identified. This review will focus on our current understanding of the chromosomal basis of male infertility specifically： chromosomal aneuploidy, structural and numerical karyotype abnormalities and Y chromosomal microdeletions. Chromosomal aneuploidy is the leading cause of pregnancy loss and developmental disabilities in humans. Aneuploidy is predominantly maternal in origin, but concerns have been raised regarding the safety of intracytoplasmic sperm injection as infertile men have significantly higher levels of sperm aneuploidy compared to their fertile counterparts. Males with numerical or structural karyotype abnormalities are also at an increased risk of producing aneuploid sperm. Our current understanding of how sperm aneuploidy translates to embryo aneuploidy will be reviewed, as well as the application of preimplantation genetic diagnosis （PGD） in such cases. Clinical recommendations where possible will be made, as well as discussion of the use of emerging array technology in PGD and its potential applications in male infertility.

Outcome of Couples with Reciprocal Translocation Carrier Undergoing the First Preimplantation Genetic Testing Cycles

Background: Reciprocal translocation(RCP) causes male infertility and female recurrent pregnancy loss. Male and female carriers have different responses to meiotic disturbances. Gender difference in outcomes of the RCP couples undergoing preimplantation genetic testing(PGT) is unknown.Methods: We conducted a retrospective analysis of 238 RCP couples(124 female and 114 male carriers) divided by gender of carrier from March 2014 to March 2017. Blastocysts were divided by day 5 and day 6. Females were divided into older(≥38 years) and younger(<38 years). Logistic regression was fitted for the relationship between gender of carriers and euploidy. Euploidy rate of each group, pregnancy rate, and live birth rate between different genders were analyzed.Results: The sperm live rate, forward motile sperm rate, and normal morphology rate of serum in male RCP group were significantly decreased. The euploidy rate was 30.30% in female group and 34.90% in male group(P = 0.131); 34.50% in day 5 group and 27.50% in day 6 group(P = 0.039); 33.40% in age <38 years group and 22.40% in age ≥38 years group(P = 0.063). Day 5(odds ratio [OR] = 1.388, 95% confidence interval [CI ] = 1.012–1.904; P = 0.042) and younger age(OR = 1.753, 95% CI = 0.97–3.17; P = 0.063) were associated with euploidy. The clinical pregnancy rate(37.90% vs. 41.20%), ongoing pregnancy rate(33.10% vs. 37.70%), and live birth rate(25.80% vs. 31.60%) per initiated were not significantly different in two gender groups.Conclusions: Although gender influence is not significant, couples with male carrier showed better clinical outcomes. The embryo growing rate and female age are important predictions estimating euploidy in RCP couples.

Single Cell Analysis of Dystrophin and SRY Gene by Using Whole Genome Amplification

ve To develop a reliable and sensitive method for detection of sex and multi-loci of Duchenne muscular dystrophy (DMD) gene in single cell

Cutting-Edge Reproductive Medicine and Ethics in Japan

Although the Japan Society of Obstetrics and Gynecology （JSOG） endorses new-type PGD using CGH for only carriers of balanced chromosomal translocations, it is against the ethical guidelines of the JSOG to decide whether or not embryos should be implanted due to aneuploidy discovered as a result of new-type PGD. In the author＇s opinion, it should be at the discretion of the JSOG＇s own randomized controlled trials, which should involve multiple facilities, whether or not a scientific basis can be found for the value of the new-type PGD in cases of recurrent miscarriage, in cases of implantation failure, and in cases where the women are of advanced maternal age. Dr. Netsu＇s 36 cases of selective reduction may be against the Japanese Maternal Health Protection Law that prohibits abortion due to congenital disease, but with the backdrop that there are many abortions that are performed as a result of parental convenience in Japan, it is difficult to understand the difference between the over 300,000 abortions that are performed every year in Japan and Dr. Netsu＇s prescribed surgery which is designed to selectively reduce fetuses with congenital disease for the purpose of evading physical danger for women with multiple gestations.

Reproductive management through integration of PGD and MPS-based noninvasive prenatal screening/diagnosis for a family with GJB2-associated hearing impairment

A couple with a proband child of GJB2 （encoding the gap junction protein connexin 26）-associated hearing impairment and a previous pregnancy miscarriage sought for a reproductive solution to bear a healthy child. Our study aimed to develop a cus- tomized preconception-to-neonate care trajectory to fulfill this clinical demand by integrating preimplantation genetic diagno- sis （PGD）, noninvasive prenatal testing （NIPT）, and noninvasive prenatal diagnosis （N1PD） into the strategy. Auditory and ge- netic diagnosis of the proband child was carried out to identify the disease causative mutations. The couple then received in-vitro-fertilization treatment, and eight embryos were obtained for day 5 biopsy. PGD was performed by short-tandem-repeat linkage analysis and Sanger sequencing of GJB2 gene. Transfer of a GJB2c.235delC heterozygous embryo resulted in a sin- gleton pregnancy. At the 13th week of gestation, genomic DNA （gDNA） from the trio family and cell-free DNA （cfDNA） from maternal plasma were obtained for assessment of fetal chromosomal aneuploidy and GJB2 mutations. NIPT and NIPD showed the absence of chromosomal aneuploidy and GJB2-associated disease in the fetus, which was later confirmed by inva- sire procedures and postnatal genetic/auditory diagnosis. This strategy successfully prevented the transmission of hearing im- pairment in the newborn, thus providing a valuable experience in reproductive management of similar cases and potentially other monogenic disorders.

Pregnancies after Transfer of Vitrified Biopsied Blastocysts

Objective To show two cases describing the successful pregnancies after transplan- tation of vitrified biopsied embryos after preimplantation genetic diagnosis （PGD）. Methods PGD by day 3 embryo biopsy was performed. Excess embryos were frozen using vitrification method. Four months later, the patient elected to undergo a frozen- thawed embryo transfer （FET） cycle. Results These two patients became pregnant and both of them delivered healthy PGD baby respectively. Conclusion This report shows that vitrification is an efficient and practical method for embryo cryopreservation during PGD. Frozen-thawed blastocysts that do survive obtained from vitrified D3 biopsied embryos are able to implant.