Birth of healthy children after preimplantation diagnosis of β-thalassemia

Background Clinical programs for preventing β-thalassemia are presently based on prospective carrier screening and prenatal diagnosis. This paper report an achievement of a pregnancy with unaffected embryos using in vitro fertilization and embryo transfer (IVF-ET), in combination with preimplantation genetic diagnosis (PGD), for a couple at risk of having children with β-thalassemia. Methods A couple carrying different thalassemia mutations, both a codon 41-42 mutation and the IVS-II-654 mutation, received standard IVF treatment, with intracytoplasmic sperm injection, embryo biopsiy, single cell polymerase chain reaction (PCR) and DNA analysis. Only unaffected or carrier embryos were transferred to the uterine cavity. After confirmation of pregnancy, a prenatal diagnosis was performed. Results Of a total of 13 embryos analyzed for β-globin mutations, PGD indicated that 2 were normal, 3 were affected, and 6 were carriers. Diagnosis could not be made in the other 2 embryos. Three embryos were transferred to the uterus on the third day after oocyte retrieval. Ultrasonography revealed a twin pregnancy with one blighted ovum. The prenatal genetic diagnosis revealed that both fetuses were unaffected, and two healthy boys were born, confirming the results of PGD. Conclusions We developed a single-cell based primer extension preamplification (PEP)-PCR assay for the detection of β-thalassemia mutations. The assays were efficient and accurate at all stages of the procedure, and resulted in the birth of PGD-confirmed β-thalassemia free children in China. PEP was used here in PGD for β-thalassemia.

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.

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)。

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.

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

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.

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.

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.