Identification and interruption of inheritance of familial cryptic translocations: A case report.

BACKGROUND: Cryptic translocations can be identified via genetic analysis of aborted tissues or malformed infants, but it is difficult to deduce the parental origins of the translocations. In the absence of such information, it is not easy to distinguish translocations from normal embryos during pre-implantation genetic testing, that seeks to block familial transmission of translocations. METHODS: Here, we present a new method that detects cryptic translocations and blocks familial transmission thereof. Whole-genome, low-coverage mate-pair sequencing (WGLMPS) revealed chromosome breakpoint sequences, and preimplantation genetic haplotyping (PGH) was then used to discard embryos with cryptic translocations. RESULTS: Cryptic translocations were found in all four families, and familial transmission was successfully blocked in one family. CONCLUSION: Whole-genome, low-coverage mate-pair sequencing combined with preimplantation genetic haplotyping methods powerfully and practically identify cryptic translocations and block familial transmissions.

Effect of noninvasive embryo viability testing versus conventional IVF on the live birth rate in IVF/ICSI patients: a study protocol for a double-blind, multicenter, randomized controlled trial.

BACKGROUND: Preimplantation genetic testing for aneuploidy (PGT-A) was demonstrated to be superior to conventional IVF in reducing the incidence of miscarriage and abnormal offspring after the first embryo transfer (ET). PGT-A requires several embryo trophectoderm cells, but its negative impacts on embryo development and long-term influence on the health conditions of conceived children have always been a concern. As an alternative, noninvasive PGT-A (niPGT-A) approaches using spent blastocyst culture medium (SBCM) achieved comparable accuracy with PGT-A in several pilot studies. The main objective of this study is to determine whether noninvasive embryo viability testing (niEVT) results in better clinical outcomes than conventional IVF after the first embryo transfer. Furthermore, we further investigated whether niEVT results in higher the live birth rate between women with advanced maternal age (AMA, > 35 years old) and young women or among patients for whom different fertilization protocols are adopted. METHODS: This study will be a double-blind, multicenter, randomized controlled trial (RCT) studying patients of different ages (20-43 years) undergoing different fertilization protocols (in vitro fertilization [IVF] or intracytoplasmic sperm injection [ICSI]). We will enroll 1140 patients at eight reproductive medical centers over 24 months. Eligible patients should have at least two good-quality blastocysts (better than grade 4 CB). The primary outcome will be the live birth rate of the first embryo transfer (ET). Secondary outcomes will include the clinical pregnancy rate, ongoing pregnancy rate, miscarriage rate, cumulative live birth rate, ectopic pregnancy rate, and time to pregnancy. DISCUSSION: In this study, patients who undergo noninvasive embryo viability testing (niEVT) will be compared to women treated by conventional IVF. We will determine the effects on the pregnancy rate, miscarriage rate, and live birth rate and adverse events. We will also investigate whether there is any difference in clinical outcomes among patients with different ages and fertilization protocols (IVF/ICSI). This trial will provide clinical evidence of the effect of noninvasive embryo viability testing on the clinical outcomes of the first embryo transfer. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR) Identifier: ChiCTR2100051408. 9 September 2021.

Concordance of PGT for aneuploidies between blastocyst biopsies and spent blastocyst culture medium.

RESEARCH QUESTION: Non-invasive preimplantation genetic testing for aneuploidies (niPGT-A) avoids the possible detrimental impact of invasive PGT-A on embryo development and clinical outcomes. Does cell-free DNA (cfDNA) from spent blastocyst culture medium (BCM) reflect embryonic chromosome status better than trophectoderm (TE) biopsy? DESIGN: In this study, 35 donated embryos were used for research and the BCM, TE biopsy, inner cell mass (ICM) and residual blastocyst (RB) were individually picked up from these embryos. Whole genome amplification (WGA) was performed and amplified DNA was subject to next-generation sequencing. Chromosome status concordance was compared among the groups of samples. RESULTS: The WGA success rates were 97.0% (TE biopsy), 100% (ICM), 97.0% (RB) and 88.6% (BCM). Using ICM as the gold standard, the chromosomal ploidy concordance rates for BCM, TE biopsy and RB were 58.33% (14/24), 68.75% (22/32) and 78.57% (22/28); the diagnostic concordance rates were 83.33% (20/24), 87.50% (28/32) and 92.86% (26/28); and the sex concordance rates were 92.31% (24/26), 100% (32/32) and 100% (28/28), respectively. Considering RB the gold standard, the chromosome ploidy concordance rates for BCM and TE biopsy were 61.90% (13/21) and 81.48% (22/27); the diagnostic concordance rates were 71.43% (15/21) and 88.89% (24/27); and the sex concordance rates were 91.30% (21/23) and 100% (27/27), respectively. CONCLUSIONS: The results of niPGT-A of cfDNA of spent BCM are comparable to those of invasive PGT-A of TE biopsies. Modifications of embryo culture conditions and testing methods will help reduce maternal DNA contamination and improve the reliability of niPGT-A.

Application of single-sperm sequencing in a male with Marfan syndrome: a case report and a literature review.

Marfan syndrome (MFS) is caused by a FBN1 mutation. Many organ systems are affected in patients with MFS, including the skeletal, ocular, cardiovascular and pulmonary systems. Cardiovascular manifestations are the main cause of mortality in patients with MFS. The mode of inheritance of MFS is autosomal dominant inheritance and the offspring are at great risk for the disease. Thus, the genetic testing for monogenic disease during preimplantation (PGT-M) is routinely advised for patients with MFS. PGT-M is a clinical genetic method to obtain normal embryos which are not affected by the monogenetic disorder. However, allele drop out (ADO) typically results in misdiagnosis during the PGT-M in the autosomal dominant disorder. Thus, a linkage analysis of polymorphic sites is used to identify ADO and improve the accuracy of PGT-M. However, when there are no family members affected, or the patients carry a de novo mutation, a linkage analysis cannot be performed to position the abnormal chromatid. Here, we performed single-sperm sequencing of preimplantation genetic testing in a male patient with MFS with a de novo mutation in FBN1. We constructed the chromosomal haplotype of the male patient by analysing information at the mutation site and at polymorphic sites. Next, the normal embryos were selected based on the results of high-throughput sequencing and haplotyping, and the one frozen embryo was transferred to the uterus. Finally, the preimplantation genetic testing results were confirmed by the prenatal genetic diagnosis during pregnancy, which showed that the foetus did not carry the pathogenic mutation. In conclusion, our research showed that single-sperm sequencing and haplotype analysis can be used in male patients with monogenetic disorders caused by de novo mutations to improve the accuracy of the preimplantation genetic diagnosis.

Divergent Alterations of Structural-Functional Connectivity Couplings in First-episode and Chronic Schizophrenia Patients.

Emerging evidence suggests that the coupling relating the structural connectivity (SC) of the brain to its functional connectivity (FC) exhibits remarkable changes during development, normal aging, and diseases. Although altered structural-functional connectivity couplings (SC-FC couplings) have been previously reported in schizophrenia patients, the alterations in SC-FC couplings of different illness stages of schizophrenia (SZ) remain largely unknown. In this study, we collected structural and resting-state functional MRI data from 73 normal controls (NCs), 61 first-episode (FeSZ) and 78 chronic (CSZ) schizophrenia patients. Positive and negative syndrome scale (PANSS) scores were assessed for all patients. Structural and functional brain networks were constructed using gray matter volume (GMV) and resting-state magnetic resonance imaging (rs-fMRI) time series measurements. At the connectivity level, the CSZ patients showed significantly increased SC-FC coupling strength compared with the FeSZ patients. At the node strength level, significant decreased SC-FC coupling strength was observed in the FeSZ patients compared to that of the NCs, and the coupling strength was positively correlated with negative PANSS scores. These results demonstrated divergent alterations of SC-FC couplings in FeSZ and CSZ patients. Our findings provide new insight into the neuropathological mechanisms underlying the developmental course of SZ.

Rare De Novo IGF2 Variant on the Paternal Allele in a Patient With Silver-Russell Syndrome.

Silver-Russell syndrome (SRS) is a rare, well-recognized disorder characterized by growth restriction, including intrauterine and postnatal growth. Most SRS cases are caused by hypomethylation of the paternal imprinting center 1 (IC1) in chromosome 11p15.5 and maternal uniparental disomy in chromosome 7 (UPD7). Here, we report on a Chinese family with a 4 year old male proband presenting with low birth weight, growth retardation, short stature, a narrow chin, delayed bone age, and speech delays, as a result of a rare molecular etiology. Whole-exome sequencing was conducted, and a novel de novo IGF2 splicing variant, NM_000612.4: c.157+5G > A, was identified on the paternal allele. In vitro functional analysis by RT-PCR and Sanger sequencing revealed that the variant leads to an aberrant RNA transcript lacking exon 2. Our results further confirm the IGF2 variant mediates SRS and expand the pathogenic variant and phenotypic spectrum of IGF2-mediated SRS. The results indicate that, beyond DNA methylation and UPD7 and CDKN1C variant tests, IGF2 gene screening should also be considered for SRS molecular diagnoses.

Novel compound heterozygous COG5 mutations in a Chinese male patient with severe clinical symptoms and type IIi congenital disorder of glycosylation: A case report.

In the current study, one case of COG5-CDG involving a Chinese male patient with severe neurological symptoms, who had previously been misdiagnosed with congenital gyrus malformation, is described. A clinical investigation was performed and targeted next-generation sequencing (NGS) was used to identify COG5 variants in the patient and his family. PCR and Sanger sequencing were performed for the verification of NGS results. The patient showed severe central and peripheral neurological symptoms, while only mild symptoms were reported in a previous reported case, in which different mutations were involved. The reported patient carried the frameshift mutation c.330delT (p.V111Lfs*22), and a missense mutation c.2324 C>T (p.P775L) in the COG5 gene. The c.330delT (p.V111Lfs*22) variant is a novel mutation, while c.2324 C>T (p.P775L) has previously been reported. Inheriting one variant from each of his parents, the current case report furthers the understanding of genotype-phenotype correlations in COG5-CDG.

[The basics of 14-3-3 protein family and research progress on therapeutic applications of 14-3-3 protein].

The 14-3-3 proteins comprise a family of highly conserved acidic protein with subunit molecular mass 28-33kD and are widely found in different eukaryotic cells. 14-3-3 proteins were the first polypeptides shown to have phosphoserine/threonine (pSer/Thr) binding properties which firmly established its importance in cell signaling. 14-3-3 proteins tend to form dimeric proteins to modulate protein-protein interactions. 14-3-3 proteins have been shown to contribute to the regulation of such crucial cellular processes as metabolism, signal transduction, cell cycle control, cell growth and differentiation, apotosis, protein trafficking, transcription, stress responses and malignant transformation. Many reports link 14-3-3 to disorders, particularly the neurological disorders and cancer. The 14-3-3 test has been used for the diagnosis of prion diseases. 14-3-3 could be exploited for therapeutic purposes. In this review, we discuss the structure, function of 14-3-3 protein and the related research progress in therapeutic applications.