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

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.

Objective:To explore the genetic etiology for a premature ovarian insufficiency (POI) patient from a consanguineous Chinese family, and to provide basis for genetic counseling and fertility counseling.Methods:Whole-exome sequencing was performed using DNA extracted from the blood sample of POI patient. Suspected pathogenic mutation was analyzed by bioinformatics methods and verified by Sanger sequencing. The pathogenicity of the variation was assessed according to the ACMG genetic variation classification criteria and guidelines.Results:A homozygous variation, c. 32G>T (p.G11V), of PSMC3IP was identified in the patient. Bioinformatics analysis revealed that the variation was conserved in different animal species, and this variation was classified as possible pathogenic variation according to the ACMG genetic variation classification criteria and guidelines.Conclusions:The homozygous missense variation of PSMC3IP is the cause of the POI patient in this family. We are reporting for the first time the missense variation in PSMC3IP gene caused POI, which enriched the mutation spectrum of PSMC3IP and provided the basis for genetic counseling and fertility guidance of this family.

OBJECTIVE: To explore the correlation between Fragile X mental retardation gene-1 (FMR1) gene CGG repeats with diminished ovarian reserve (DOR). METHODS: For 214 females diagnosed with DOR, DNA was extracted from peripheral blood samples. FMR1 gene CGG repeats were determined by PCR and capillary electrophoresis. RESULTS: Three DOR patients were found to carry FMR1 premutations, and one patient was found to carry gray zone FMR1 repeats. After genetic counseling, one patient and the sister of another patient, both carrying FMR1 permutations, conceived naturally. Prenatal diagnosis showed that both fetuses have carried FMR1 permutations. CONCLUSION FMR1 gene permutation may be associated with DOR. Determination of FMR1 gene CGG repeats in DOR patients can provide a basis for genetic counseling and guidance for reproduction.
Female ; Fragile X Mental Retardation Protein/metabolism* ; Fragile X Syndrome/genetics* ; Humans ; Ovarian Diseases ; Ovarian Reserve/genetics* ; Primary Ovarian Insufficiency/genetics* ; Trinucleotide Repeats/genetics*

OBJECTIVE: To analyze the (CGG)n repeats of FMR1 gene among patients with unexplained mental retardation. METHODS: For 201 patients with unexplained mental retardation, the (CGG)n repeats of the FMR1 gene were analyzed by PCR and FragilEase RESULTS: For the 201 patients with unexplained mental retardation, 15 were identified with full mutations of the FMR1 gene. The prevalence of fragile X syndrome (FXS) in patients with unexplained mental retardation was determined as 7.5% (15/201). Prenatal diagnosis was provided for 6 pregnant women with pre- or full mutations. Analysis revealed that women with mental retardation and full FMR1 mutations exhibited a skewed XCI pattern with primary expression of the X chromosome carrying the mutant allele. CONCLUSION FXS has a high incidence among patients with unexplained mental retardation. Analysis of FMR1 gene (CGG)n repeats in patients with unexplained mental retardation can facilitate genetic counseling and prenatal diagnosis for their families. FMR1 gene (CGG)n repeats screening should be recommended for patients with unexplained mental retardation.
Female ; Fragile X Mental Retardation Protein/genetics* ; Fragile X Syndrome/genetics* ; Humans ; Intellectual Disability/genetics* ; Mutation ; Pregnancy ; Prenatal Diagnosis

OBJECTIVETo determine the molecular etiology for a Chinese pedigree affected with epidermolysis bullosa simplex (EBS).

METHODSTarget region sequencing using a hereditary epidermolysis bullosa capture array combined with Sanger sequencing and bioinformatics analysis were used. Mutation taster, PolyPhen-2, Provean, and SIFT software and NCBI online were employed to assess the pathogenicity and conservation of detected mutations. One hundred healthy unrelated individuals were used as controls.

RESULTSTarget region sequencing showed that the proband has carried a unreported heterozygous c.1234A>G (p.Ile412Val) mutation of the KRT14 gene, which was confirmed by Sanger sequencing in other 8 affected individuals but not among healthy members of the pedigree. Bioinformatics analysis indicated that the mutation is highly pathogenic. Remarkably, 3 members of the family (2 affected and 1 unaffected) have carried a heterozygous c.1237G>A (p.Ala413Thr) mutation of the KRT14 gene, which was collected in Human Gene Mutation Database (HGMD). Bioinformatics analysis indicated that the mutation may not be pathogenic. Both mutations were not detected among the 100 healthy controls.

CONCLUSIONThe novel c.1234A>G(p.Ile412Val) mutation of the KRT14 gene is probably responsible for the disease, while c.1237G>A (p.Ala413Thr) mutation of KRT14 gene may be a polymorphism. Compared with Sanger sequencing, target region capture sequencing is more efficient and can significantly reduce the cost of genetic testing for EBS.

Adult ; Amino Acid Sequence ; Case-Control Studies ; Epidermolysis Bullosa Simplex ; genetics ; Female ; Humans ; Keratin-14 ; genetics ; Male ; Mutation ; genetics ; Pedigree ; Young Adult

OBJECTIVETo screen for FOXL2 gene mutations in 6 patients with blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES), and explore their genotype-phenotype correlation.

METHODSPeripheral venous blood samples were collected from the patients for the extraction of genomic DNA. PCR and Sanger sequencing were employed to analyze the coding region and flanking sequences of the FOXL2 gene. Pathogenicity of the identified mutations was verified through literature review and bioinformatic analysis.

RESULTSA heterozygous c.672_701dup30 mutation was found in the probands from the two familial cases, while three heterozygous mutations (two were novel), namely c.462_468del (p.Pro156Argfs*113), c.251T to A (p.Ile84Asn) and c.988_989insG (p.Ala330Glyfs*204) were detected in the three sporadic cases. Literature review and bioinformatic analysis indicated that all these mutations are pathogenic.

CONCLUSIONIdentification of causative mutations in the BPES patients has provided a basis for genetic counseling and reproductive guidance. The novel mutations have enriched the mutation spectrum of the FOXL2 gene.

Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Blepharophimosis ; diagnosis ; genetics ; China ; Female ; Forkhead Box Protein L2 ; Forkhead Transcription Factors ; genetics ; Genetic Association Studies ; Humans ; Male ; Molecular Sequence Data ; Pedigree ; Skin Abnormalities ; diagnosis ; genetics ; Urogenital Abnormalities ; diagnosis ; genetics ; Young Adult