OBJECTIVE: To explore the genetic etiology of 46 Chinese pedigrees affected with Hereditary multiple exostoses (HME) and provide genetic counseling and reproductive intervention. METHODS: Whole-exome sequencing and Sanger sequencing were carried out on 87 patients from the 46 pedigrees to analyze the variants of EXT1 and EXT2 genes. Pathogenicity of the variants was assessed based on the guidelines from the American College of Medical Genetics and Genomics and Association for Molecular Pathology (ACMG/AMP). Prenatal diagnosis and preimplantation genetic testing (PGT) were provided for couples with identified pathogenic mutations. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: LL-SC-SG-2014-010). RESULTS: In total 17 and 22 pathogenic variants were respectively identified in the EXT1 and EXT2 genes, among which 5 EXT1 and 12 EXT2 variants were unreported previously. Three patients with no family history were found to harbor de novo variants of the EXT1 gene. Twenty nine couples had opted for PGT or underwent prenatal diagnosis following natural conception, and 17 healthy babies were born. CONCLUSION This study has clarified the genetic etiology of 45 HME pedigrees and identified 17 novel variants, which has enriched the mutational spectrum of the EXT1 and EXT2 genes. Reproductive intervention through PGT and prenatal diagnosis have prevented the recurrence of HME in these families.
Humans ; Female ; Male ; Pedigree ; Exostoses, Multiple Hereditary/diagnosis* ; N-Acetylglucosaminyltransferases/genetics* ; Adult ; Exostosin 1 ; Asian People/genetics* ; Genetic Testing ; Exostosin 2 ; Mutation ; China ; Prenatal Diagnosis ; Pregnancy ; Genetic Counseling ; Preimplantation Diagnosis ; Exome Sequencing ; East Asian People

Epigenetics is the link between the genome and environment, which can respond to physiological (such as age) or environmental factors (such as diet, stress, and pollution) and induce changes in epigenetic modifications (such as DNA methylation, non-coding RNA, and histone modifications). It can also serve as cellular memory transmitted from generation to generation. Sperm is highly responsive to such environmental changes and has unique epigenetic profiles. The paternal inter-/trans-generational inheritance mediated by sperm epigenetic changes is closely related to the health of offspring, which is an issue of great concern. This review has summarized the epigenetic mechanisms of paternal inter-/trans-generational inheritance and recent studies on the paternal inheritance mediated by sperm epigenetic changes in human and mice, which may facilitate understanding of the relationship between paternal epigenetic changes and the health of offspring caused by physiological or environmental changes and provide a basis for genetic counseling and clinical intervention.
Epigenesis, Genetic ; Humans ; Male ; Animals ; Spermatozoa/metabolism* ; DNA Methylation ; Paternal Inheritance ; Mice

Epigenetics is the link between the genome and environment, which can respond to physiological (such as age) or environmental factors (such as diet, stress, and pollution) and induce changes in epigenetic modifications (such as DNA methylation, non-coding RNA, and histone modifications). It can also serve as cellular memory transmitted from generation to generation. Sperm is highly responsive to such environmental changes and has unique epigenetic profiles. The paternal inter-/trans-generational inheritance mediated by sperm epigenetic changes is closely related to the health of offspring, which is an issue of great concern. This review has summarized the epigenetic mechanisms of paternal inter-/trans-generational inheritance and recent studies on the paternal inheritance mediated by sperm epigenetic changes in human and mice, which may facilitate understanding of the relationship between paternal epigenetic changes and the health of offspring caused by physiological or environmental changes and provide a basis for genetic counseling and clinical intervention.

Epigenetics is the link between the genome and environment, which can respond to physiological (such as age) or environmental factors (such as diet, stress, and pollution) and induce changes in epigenetic modifications (such as DNA methylation, non-coding RNA, and histone modifications). It can also serve as cellular memory transmitted from generation to generation. Sperm is highly responsive to such environmental changes and has unique epigenetic profiles. The paternal inter-/trans-generational inheritance mediated by sperm epigenetic changes is closely related to the health of offspring, which is an issue of great concern. This review has summarized the epigenetic mechanisms of paternal inter-/trans-generational inheritance and recent studies on the paternal inheritance mediated by sperm epigenetic changes in human and mice, which may facilitate understanding of the relationship between paternal epigenetic changes and the health of offspring caused by physiological or environmental changes and provide a basis for genetic counseling and clinical intervention.

Objective:To carry out cytogenetic and molecular genetic analysis for two infertile patients carrying rare small supernumerary marker chromosomes (sSMC).Methods:Two infertile patients who received reproductive and genetic counseling at CITIC Xiangya Reproductive and Genetic Hospital on October 31, 2018 and May 10, 2021, respectively were selected as the study subjects. The origin of sSMCs was determined by conventional G banding, fluorescence in situ hybridization (FISH) and copy number variation sequencing (CNV-seq). Microdissection combined with high-throughput whole genome sequencing (MicroSeq) was carried out to determine the fragment size and genomic information of their sSMCs. Results:For patient 1, G-banded karyotyping and FISH revealed that he has a karyotype of mos47, XY, del(16)(p10p12), + mar[65]/46, XY, del(16)(p10p12)[6]/48, XY, del(16)(p10p12), + 2mar[3].ish mar(Tel 16p-, Tel 16q-, CEP 16-, WCP 16+ ). CNV analysis has yielded a result of arr[GRCh37]16p12.1p11.2(24999364_33597595)×1[0.25]. MicroSeq revealed that his sSMC has contained the region of chromosome 16 between 24979733 and 34023115 (GRCh37). For patient 2, karyotyping and reverse FISH revealed that she has a karyotype of mos 47, XX, + mar[37]/46, XX[23].rev ish CEN5, and CNV analysis has yielded a result of seq[GRCh37]dup(5)(p12q11.2)chr5: g(45120001_56000000)dup[0.8]. MicroSeq results revealed that her sSMC has contained the region of chromosome 5 between 45132364 and 55967870(GRCh37). After genetic counseling, both couples had opted in vitro fertilization (IVF) treatment and preimplantation genetic testing (PGT). Conclusion:For individuals harboring sSMCs, it is vital to delineate the origin and structural characteristics of the sSMCs for their genetic counseling and reproductive guidance. Preimplantation genetic testing after microdissection combined with high-throughput whole genome sequencing (MicroSeq-PGT) can provide an alternative treatment for carrier couples with a high genetic risk.

Primary ciliary dyskinesia (PCD) is a congenital, motile ciliopathy with pleiotropic symptoms. Although nearly 50 causative genes have been identified, they only account for approximately 70% of definitive PCD cases. Dynein axonemal heavy chain 10 (DNAH10) encodes a subunit of the inner arm dynein heavy chain in motile cilia and sperm flagella. Based on the common axoneme structure of motile cilia and sperm flagella, DNAH10 variants are likely to cause PCD. Using exome sequencing, we identified a novel DNAH10 homozygous variant (c.589C > T, p.R197W) in a patient with PCD from a consanguineous family. The patient manifested sinusitis, bronchiectasis, situs inversus, and asthenoteratozoospermia. Immunostaining analysis showed the absence of DNAH10 and DNALI1 in the respiratory cilia, and transmission electron microscopy revealed strikingly disordered axoneme 9+2 architecture and inner dynein arm defects in the respiratory cilia and sperm flagella. Subsequently, animal models of Dnah10-knockin mice harboring missense variants and Dnah10-knockout mice recapitulated the phenotypes of PCD, including chronic respiratory infection, male infertility, and hydrocephalus. To the best of our knowledge, this study is the first to report DNAH10 deficiency related to PCD in human and mouse models, which suggests that DNAH10 recessive mutation is causative of PCD.
Humans ; Male ; Animals ; Mice ; Semen/metabolism* ; Dyneins/metabolism* ; Cilia/metabolism* ; Mutation ; Ciliary Motility Disorders/genetics*

OBJECTIVE: To summarize the genetic characteristics of 671 Chinese pedigrees affected with Duchenne/Becker muscular dystrophy (DMD/BMD). METHODS: Clinical data of the pedigrees were collected. Multiplex PCR, multiple ligation dependent probe amplification (MLPA), next generation sequencing (NGS), Sanger sequencing and long read sequencing were used to detect the variant of DMD gene in the probands and their mothers, and prenatal diagnosis was provided for high risk pregnant women. RESULTS: Among 178 pedigrees analyzed by multiplex PCR, 44 variants of the DMD gene were detected, with the genetic diagnosis attained in 110 pedigrees. Among 493 pedigrees analyzed by MLPA in combination with NGS or Sanger sequencing, 294 pathogenic/possible pathogenic variants were identified, among which 45 were unreported previously, and the genetic diagnosis attained in 484 pedigrees. Structural variants of the DMD gene were identified in two pedigrees by long-read sequencing. Among 444 probands, 341 have inherited the DMD gene variant from their mothers (76.8%). Among 390 women with a high-risk, 339 have opted to have natural pregnancy and 51 chose preimplantation genetic testing for monogenetic disease (PGT-M). The detection rate of neonatal patients and carriers following natural pregnancy was significantly higher than that for PGT-M. CONCLUSION Combined application of MLPA, NGS, Sanger sequencing and long-read sequencing is an effective strategy to detect DMD/BMD. PGT-M can effectively reduce the risk of fetuses. Above finding has expanded the spectrum of DMD gene variants and provided a basis for reproductive intervention for pregnancies with a high risk for DMD/BMD.
China ; Dystrophin/genetics* ; Exons ; Female ; Genetic Testing ; Humans ; Infant, Newborn ; Multiplex Polymerase Chain Reaction ; Muscular Dystrophy, Duchenne/genetics* ; Mutation ; Pedigree ; Pregnancy ; Prenatal Diagnosis

OBJECTIVE: To determine the carrier rate for 21 inherited metabolic diseases among a Chinese population of childbearing age. METHODS: A total of 897 unrelated healthy individuals (including 143 couples) were recruited, and DNA was extracted from their peripheral blood samples. Whole exome sequencing (WES) was carried out to screen potential variants among 54 genes associated with 21 inherited metabolic diseases. Pathogenic and likely pathogenic variants and unreported loss-of-function variants were analyzed. RESULTS: One hundred fourty types of pathogenic/likely pathogenic variants (with an overall number of 183) and unreported loss-of-function variants were detected, which yield a frequency of 0.20 per capita. A husband and wife were both found to carry pathogenic variants of the SLC25A13 gene and have given birth to a healthy baby with the aid of preimplantation genetic diagnosis. The detected variants have involved 40 genes, with the most common ones including ATP7B, SLC25A13, PAH, CBS and MMACHC. Based on the Hardy-Weinberg equilibrium, the incidence of the 21 inherited metabolic diseases in the population was approximately 1/1100, with the five diseases with higher incidence including citrullinemia, methylmalonic acidemia, Wilson disease, glycogen storage disease, and phenylketonuria. CONCLUSION This study has preliminarily determined the carrier rate and incidence of 21 inherited metabolic diseases among a Chinese population of childbearing age, which has provided valuable information for the design of neonatal screening program for inherited metabolic diseases. Pre-conception carrier screening can provide an important measure for the prevention of transmission of Mendelian disorders in the population.
Asians/genetics* ; China ; Exome ; Female ; Humans ; Infant, Newborn ; Metabolic Diseases/genetics* ; Mitochondrial Membrane Transport Proteins/genetics* ; Oxidoreductases/genetics* ; Whole Exome Sequencing

Objective:To explore the strategy of preimplantation genetic testing for monogenic disorders (PGT-M) with variants of uncertain significance (VUS).Methods:Monogenic disorder couples who carried VUS and sought fertility counseling between 2018 and 2020 in Reproductive and Genetic Hospital of CITIC-Xiangya were recruited in this study. The pathogenicity of VUS was reanalyzed according to the Standards and Guidelines for the Interpretation of Sequence Variants released by the American College of Medical Genetics and Genomics (ACMG) and the Bayesian Classification. Those VUSs were reclassified as "pathogenic/likely pathogenic variants (P/LP)", "likely pathogenic VUS", "variants of uncertain significance", or "likely benign VUS". PGT-M was applied to families with VUS upgraded as "P/LP" or "likely pathogenic VUS" under the principle of couples fully voluntary and understanding the risks. We also followed up the developmental status of fetuses and the health condition of the born children.Results:1) A total of 25 variants were detected in 16 families with monogenic disorders, including 1 P, 3 LP, and 21 VUS. After reanalysis, 11 VUS and 7 VUS were upgraded as LP (52.4%) and "likely pathogenic VUS" (33.3%), respectively. Two VUS were still reclassified as "variants of uncertain significance"(9.5%), and 1 VUS was reclassified as "likely benign VUS" (4.8%). 2) PGT-M was implemented for 14 families with monogenic disorders, including 9 families with VUS upgraded as LP, 2 families with one LP/P and one "likely pathogenic VUS", and 3 families with only "likely pathogenic VUS". 3) Twelve healthy babies were born after PGT-M. Following up was done according to the onset age of diseases: 8 offsprings did not show the symptoms as probands, and 4 offsprings had not yet reached the age of onset and need continuous follow-up.Conclusion:It is necessary to actively search for new evidence and reanalyze the pathogenicity of VUS according to ACMG guidelines before PGT-M. Under fully informed consent of the patients, PGT-M can be carried out for VUS reclassified as "P/LP" and "likely pathogenic VUS", to reduce the risk of recurrence.

Objective:To explore the strategy of preimplantation genetic testing for monogenic disorders (PGT-M) with variants of uncertain significance (VUS).Methods:Monogenic disorder couples who carried VUS and sought fertility counseling between 2018 and 2020 in Reproductive and Genetic Hospital of CITIC-Xiangya were recruited in this study. The pathogenicity of VUS was reanalyzed according to the Standards and Guidelines for the Interpretation of Sequence Variants released by the American College of Medical Genetics and Genomics (ACMG) and the Bayesian Classification. Those VUSs were reclassified as "pathogenic/likely pathogenic variants (P/LP)", "likely pathogenic VUS", "variants of uncertain significance", or "likely benign VUS". PGT-M was applied to families with VUS upgraded as "P/LP" or "likely pathogenic VUS" under the principle of couples fully voluntary and understanding the risks. We also followed up the developmental status of fetuses and the health condition of the born children.Results:1) A total of 25 variants were detected in 16 families with monogenic disorders, including 1 P, 3 LP, and 21 VUS. After reanalysis, 11 VUS and 7 VUS were upgraded as LP (52.4%) and "likely pathogenic VUS" (33.3%), respectively. Two VUS were still reclassified as "variants of uncertain significance"(9.5%), and 1 VUS was reclassified as "likely benign VUS" (4.8%). 2) PGT-M was implemented for 14 families with monogenic disorders, including 9 families with VUS upgraded as LP, 2 families with one LP/P and one "likely pathogenic VUS", and 3 families with only "likely pathogenic VUS". 3) Twelve healthy babies were born after PGT-M. Following up was done according to the onset age of diseases: 8 offsprings did not show the symptoms as probands, and 4 offsprings had not yet reached the age of onset and need continuous follow-up.Conclusion:It is necessary to actively search for new evidence and reanalyze the pathogenicity of VUS according to ACMG guidelines before PGT-M. Under fully informed consent of the patients, PGT-M can be carried out for VUS reclassified as "P/LP" and "likely pathogenic VUS", to reduce the risk of recurrence.