Scientists Correct a Pathogenic Gene Mutation in Human Embryos.

Researchers in the United States have successfully used a gene editing technique in early stage human embryos to correct a mutation that causes hypertrophic cardiomyopathy, a report in Nature has...

Correction of the Marfan Syndrome Pathogenic FBN1 Mutation by Base Editing in Human Cells and Heterozygous Embryos.

Supercilious cell cycles in the human embryo

Are the kinase feedback loops that regulate activation and centromeric targeting of the chromosomal passenger complex (CPC), functional during mitosis in human embryos? Investigation of the regulatory kinase pathways involved in centromeric CPC targeting revealed normal phosphorylation dynamics of histone H2A at T120 (H2ApT120) by Bub1 kinase and subsequent recruitment of Shugoshin, but phosphorylation of histone H3 at threonine 3 (H3pT3) by Haspin failed to show the expected centromeric enrichment on metaphase chromosomes in the zygote. Human cleavage stage embryos show high levels of chromosomal instability. What causes this high error rate is unknown, as mechanisms used to ensure proper chromosome segregation in mammalian embryos are poorly described. In this study, we investigated the pathways regulating CPC targeting to the inner centromere in human embryos. We characterized the distribution of the CPC in relation to activity of its two main centromeric targeting pathways: the Bub1-H2ApT120-Sgo-CPC and Haspin-H3pT3-CPC pathways. The study was conducted between May 2012 and March 2014 on human surplus embryos resulting from in vitro fertilization treatment and donated for research. In zygotes, nuclear envelope breakdown was monitored by time-lapse imaging to allow timed incubations with specific inhibitors to arrest at prometaphase and metaphase, and to interfere with Haspin and Aurora B/C kinase activity. Functionality of the targeting pathways was assessed through characterization of histone phosphorylation dynamics by immunofluorescent analysis, combined with gene expression by RT-qPCR and immunofluorescent localization of key pathway proteins. Immunofluorescent analysis of the CPC subunit Inner Centromere Protein revealed the pool of stably bound CPC proteins was not strictly confined to the inner centromere of prometaphase chromosomes in human zygotes, as observed in later stages of preimplantation development and somatic cells. Investigation of the regulatory kinase pathways involved in centromeric CPC targeting revealed normal phosphorylation dynamics of histone H2A at T120 (H2ApT120) by Bub1 kinase and subsequent recruitment of Shugoshin. However, phosphorylation of histone H3 at threonine 3 (H3pT3) by Haspin kinase failed to show the expected centromeric enrichment on metaphase chromosomes in the zygote, but not at later stages. Inhibition of Haspin revealed this activity to be essential for proper mitotic checkpoint complex activation in human zygotes, thus demonstrating an active mitotic checkpoint under normal conditions. Abolishment of H3pT3 during zygotic prometaphase further shows that centromeric H2ApT120 alone is not sufficient for proper shugoshin and CPC localization. As the removal of H3pT3 from the chromosome arms during prometaphase normally contributes to further centromeric enrichment of the CPC in somatic cells, CPC targeting may be less accurate in human zygotes. Owing to ethical limitations, tripronuclear zygotes were used in functional experiments. Although these represent the best available models, it is unknown if they are completely representative for dipronuclear zygotes. In addition, further research is needed to determine to what extent the differences we observed in H3T3 phosphorylation dynamics and CPC localization affect chromosome attachment. In the zygote, paternal and maternal chromosomes coming from two separate pronuclei, and with contrasting epigenetic signatures, need to be aligned on a single metaphase plate. Our results suggest that adaptations in mechanisms regulating CPC targeting exist in the human zygote, to ensure symmetric recruitment despite the epigenetic asymmetry between maternal and paternal chromosomes. This adaptation may come at a price regarding chromosome segregation fidelity. This study was funded by the Portuguese Fundação para a Ciência e Tecnologia and the Netherlands Organization for Scientific Research. The authors have no conflicts of interest to declare.

2011;58;2703-2738; originally published online Nov 8, 2011; J. Am. Coll. Cardiol. W. Yancy Rakowski, Christine E. Seidman, Jeffrey A. Towbin, James E. Udelson, and Clyde Fifer, Mark S. Link, Srihari S. Naidu, Rick A. Nishimura, Steve R. Ommen, Harry Bernard J. Gersh, Barry J. Maron, Robert O. Bonow, Joseph A. Dearani, Michael A. Thoracic Surgeons Society for Cardiovascular Angiography and Interventions, and Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, of Thoracic Surgery, American Society of Echocardiography, American Society Developed in Collaboration With the American Association for Guidelines Cardiology Foundation/American Heart Association Task Force on Practice Cardiomyopathy: Executive Summary: A Report of the American College of 2011 ACCF/AHA Guideline for the Diagnosis and Treatment of Hypertrophic This information is current as of May 14, 2012 http://content.onlinejacc.org/cgi/content/full/58/25/2703 located on the World Wide Web at: The online version of this article, along with updated information and services, is

In vitro fertilization (IVF) represents an extraordinary advance in reproductive medicine, offering an alternative for couples who face difficulties in conceiving naturally, a condition that affects millions of people around the world. Despite all the advances in the technique, there is still concern about the possible transmission of hereditary genetic disorders to offspring, which can compromise the success of the treatment and impact the quality of life of future children. To this end, Preimplantation Genetic Diagnosis (PGD) was developed, a sophisticated technique that allows the identification of chromosomal anomalies and genetic mutations in embryos before their transfer to the patient's uterus, preventing aneuploidy, recurrent miscarriages, and especially providing specific care for women of advanced maternal age, who are at greater risk of generating embryos with chromosomal alterations. PGD uses several high-precision methodologies, such as next-generation sequencing and array comparative genomic hybridization, which provide a detailed and highly accurate analysis of embryonic genetic material. The aim of this review was to comprehensively evaluate the efficacy and safety of the different PGD techniques used in IVF procedures, examining their direct impact on embryo implantation rates, gestational success rates, and the possible adverse effects of these interventions on embryonic development. In view of the above, it is concluded that this technology ensures that embryos with the greatest potential for healthy development are selected, significantly increasing the chances of a successful IVF treatment.

Germline development from human pluripotent stem cells toward disease modeling of infertility

EDITOR—Wald and Law assert that coronary artery disease, rather than hypertrophic cardiomyopathy, is the most common cause of sudden and unexpected cardiac death in the young. Our differing conclusions were...

Molecular Characterization and Clinical Outcomes of Young Adult Patients (≤45 years old) with Philadelphia-Negative Myeloproliferative Neoplasms

Inherited cardiac diseases, including cardiomyopathies and channelopathies, are major contributors to morbidity and sudden cardiac death. Conditions such as long QT syndrome, hypertrophic cardiomyopathy, and dilated cardiomyopathy result from mutations in genes like KCNQ1, KCNH2, and MYBPCF3. X-linked disorders such as danon (lysosomal-associated membrane protein 2) and fabry (generalized lymphatic anomaly) also cause systemic cardiomyopathy. The genetic and phenotypic variability of these disorders highlights the importance of reviewing current diagnostic and treatment strategies. A thorough review of over 40 peer-reviewed articles published between 2010 and 2025 was performed. These included clinical studies, preclinical research, and reviews focusing on genetic mechanisms, disease models, and gene-editing techniques in inherited cardiac conditions. Selected sources emphasized relevance to molecular pathology, therapeutic options, ethical or regulatory issues, minimization, and graft survival. While PSC-CMs and gene editing hold promising therapeutic potential, translating these approaches into human treatments requires improved delivery methods, extensive safety testing, and long-term evaluation. Genome-editing and iPSC technologies are powerful tools for understanding and treating inherited cardiac diseases. Somatic gene editing is generally feasible, whereas germline modifications face ethical and legal obstacles.

Inherited cardiomyopathy is the major cause of sudden cardiac death (SCD) and heart failure (HF). The disease is associated with extensive genetic heterogeneity; pathogenic mutations in cardiac sarcomere protein genes, cytoskeletal protein genes and nuclear envelope protein genes have been linked to its etiology. Early diagnosis is conducive to clinical monitoring and allows for presymptomatic interventions as needed. In the present study, the entire coding sequences and flanking regions of 12 major disease (cardiomyopathy)-related genes [namely myosin, heavy chain 7, cardiac muscle, β (MYH7); myosin binding protein C, cardiac (MYBPC3); lamin A/C (LMNA); troponin I type 3 (cardiac) (TNNI3); troponin T type 2 (cardiac) (TNNT2); actin, α, cardiac muscle 1 (ACTC1); tropomyosin 1 (α) (TPM1); sodium channel, voltage gated, type V alpha subunit (SCN5A); myosin, light chain 2, regulatory, cardiac, slow (MYL2); myosin, heavy chain 6, cardiac muscle, α (MYH6); myosin, light chain 3, alkali, ventricular, skeletal, slow (MYL3); and protein kinase, AMP-activated, gamma 2 non-catalytic subunit (PRKAG2)] in 8 patients with dilated cardiomyopathy (DCM) and in 8 patients with hypertrophic cardiomyopathy (HCM) were amplified and then sequenced using the Ion Torrent Personal Genome Machine (PGM) system. As a result, a novel heterozygous mutation (MYH7, p.Asn885Thr) and a variant of uncertain significance (TNNT2, p.Arg296His) were identified in 2 patients with HCM. These 2 missense mutations, which were absent in the samples obtained from the 200 healthy control subjects, altered the amino acid that was evolutionarily conserved among a number of vertebrate species; this illustrates that these 2 non-synonymous mutations play a role in the pathogenesis of HCM. Moreover, a double heterozygous mutation (PRKAG2, p.Gly100Ser plus MYH7, p.Arg719Trp) was identified in a patient with severe familial HCM, for the first time to the best of our knowledge. This patient provided us with more information regarding the genotype-phenotype correlation between mutations of MYH7 and PRKAG2. Taken together, these findings provide insight into the molecular mechanisms underlying inherited cardiomyopathy. The mutations identified in this study may be further investigated in the future in order to improve the diagnosis and treatment of patients with inherited cardiomyopathy. Furthermore, our findings indicated that sequencing using the Ion Torrent PGM system is a useful approach for the identification of pathogenic mutations associated with inherited cardiomyopathy, and it may be used for the risk evaluation of individuals with a possible susceptibility to inherited cardiomyopathy.

Correction of the pathogenic mutation in TGM1 gene by adenine base editing in mutant embryos

Hypertrophic Cardiomyopathy (HCM) is one of primary cardiac disorders characterized by asymmetric thickening of the septum and left ventricular wall.HCM affects 1 in 500 individuals in the general population,and it is the most common cause of sudden death in the young and athletes.HCM is generally considered as anautosomal dominant inherited disease and caused by gene mutations.To date,about 450 mutations have been reported to be related HCM,which were mainly located in genes encoding cardiac sarcomere protein.In addition,more and more mitochondrial DNA mutations and modifier genes were reported to be associated with the pathogenesis of HCM.This review will focuses on the research in the genes related to HCM and their recent advances. Key words: Hypertrophic cardiomyopathy; Gene mutations; Pathogenesis

The adenine nucleotide translocases (Ant) facilitate the transport of ADP and ATP by an antiport mechanism across the inner mitochondrial membrane, thus playing an essential role in cellular energy metabolism. We recently identified a novel member of the Ant family in mouse, Ant4, of which gene configuration as well as amino acid homology is well conserved among mammals. The conservation of Ant4 in mammals, along with the absence of Ant4 in nonmammalian species, suggests a unique and indispensable role for this ADP/ATP carrier in mammalian development. Of interest, in contrast to its paralog Ant2, which is encoded by the X chromosome and ubiquitously expressed in somatic cells, Ant4 is encoded by an autosome and selectively expressed in testicular germ cells. Immunohistochemical examination as well as RNA expression analysis using separated spermatogenic cell types revealed that Ant4 expression was particularly high in spermatocytes. When we generated Ant4-deficient mice by targeted disruption, a significant reduction in testicular size was observed without any other distinguishable abnormalities in the mice. Histological examination as well as stage-specific gene expression analysis in adult and neonatal testes revealed a severe reduction of spermatocytes accompanied by increased apoptosis. Subsequently, the Ant4-deficient male mice were infertile. Taken together, these data elucidated the indispensable role of Ant4 in murine spermatogenesis. Considering the unique conservation and chromosomal location of the Ant family genes in mammals, the Ant4 gene may have arisen in mammalian ancestors and been conserved in mammals to serve as the sole and essential mitochondrial ADP/ATP carrier during spermatogenesis where the sex chromosome-linked Ant2 gene is inactivated.

Introduction: Pathological Q waves are considered harbingers of cardiac pathology and should instigate comprehensive evaluation of athletes. Several definitions of the depth or duration of a Q wave exist, with disagreement between scientific bodies as to the most useful. Objectives: 1. Determine the prevalence of pathological Q waves in large cohorts of the general population, athletes and patients with hypertrophic cardiomyopathy (HCM). 2. Identify the most accurate Q wave criterion. Methods: ECGs were retrospectively analysed in consecutive cohorts of 10,008 healthy young athletes (14-35 years old), 2,994 healthy young non-athletes and 468 HCM patients. Results: Pathological Q waves that fulfilled at least one of the 4 individual definitions (Table 1) were identified in 0.7% athletes (n = 75), 1.2% non-athletes (n = 36) and 22.6% patients with HCM (n = 106). In the healthy athletic and non-athletic population, all pathological Q waves (n = 111) met the >3mm depth definition. In contrast, the majority of pathological Q waves in HCM patients met the ≥40msec duration definition (n = 75; 70.75%). We tested the ability of all 4 criteria to distinguish between health and disease in the entire cohort. Seattle and Refined had the best sensitivity for detecting HCM. Refined criteria however, had a significantly higher positive predictive value and 7 times lower false positive rate compared to Seattle. (Table 2) Conclusion: Pathological Q waves are present in up to 1.2% of healthy young individuals and do not correlate with physical activity. Of the proposed criteria, the Refined criteria has the lowest false positive rate and should be utilised in the context of cardiac evaluation in young athletes.