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.

OBJECTIVE: To explore the genetic basis for 7 families with gonadal mosaicism for Duchenne muscular dystrophy (DMD). METHODS: For the 7 families presented at the CITIC Xiangya Reproductive and Genetic Hospital from September 2014 to March 2022, clinical data were collected. Preimplantation genetic testing for monogenic disorders (PGT-M) was carried out for the mother of the proband from family 6. Peripheral venous blood samples of the probands, their mothers and other patients from the families, amniotic fluid samples from families 1 ~ 4 and biopsied cells of embryos cultured in vitro from family 6 were collected for the extraction of genomic DNA. Multiplex ligation-dependent probe amplification (MLPA) was carried out for the DMD gene, and short tandem repeat (STR)/single nucleotide polymorphism (SNP)-based haplotypes were constructed for the probands, other patients, fetuses and embryos. RESULTS: The results of MLPA showed that the probands and the fetuses/probands' brothers in families 1 ~ 4, 5, 7 had carried the same DMD gene variants, whilst the probands' mothers were all normal. The proband in family 6 carried the same DMD gene variant with only 1 embryo (9 in total) cultured in vitro, and the DMD gene of the proband's mother and the fetus obtained through the PGT-M were normal. STR-based haplotype analysis showed that the probands and the fetuses/probands' brothers in families 1 ~ 3 and 5 have inherited the same maternal X chromosome. SNP-based haplotype analysis showed that the proband from family 6 has inherited the same maternal X chromosome with only 1 embryo (9 in total) cultured in vitro. The fetuses in families 1 and 6 (via PGT-M) were both confirmed to be healthy by follow up, whilst the mothers from families 2 and 3 had chosen induced labor. CONCLUSION Haplotype analysis based on STR/SNP is an effective method for judging gonad mosaicism. Gonad mosaicisms should be suspected for women who have given births to children with DMD gene variants but with a normal peripheral blood genotype. Prenatal diagnosis and reproductive intervention may be adapted to reduce the births of further affected children in such families.
Male ; Pregnancy ; Child ; Humans ; Female ; Muscular Dystrophy, Duchenne/diagnosis* ; Dystrophin/genetics* ; Mosaicism ; Exons ; Prenatal Diagnosis/methods* ; Nucleotides

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 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*

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 explore the genetic etiology of three families affected with split-hand/split-foot malformation (SHFM).

METHODSPeripheral venous blood samples from 21 members of pedigree 1, 2 members of pedigree 2, and 2 members of pedigree 3 were collected. PCR-Sanger sequencing, microarray chip, fluorescence in situ hybridization (FISH), real-time PCR, and next-generation sequencing were employed to screen the mutations in the 3 families. The effect of the identified mutations on the finger (toe) abnormality were also explored.

RESULTSMicroarray and real-time PCR analysis has identified a duplication in all patients from pedigrees 1 and 3, which have spanned FKSG40, TLX1, LBX1, BTRC, POLL and FBXW4 (exons 6-9) and LBX1, BTRC, POLL and FBXW4 (exons 6-9) genes, respectively. A missense mutation of the TP63 gene, namely c.692A>G (p.Tyr231Cys), was found in two patients from pedigree 2. FISH analysis of chromosome 10 showed that the rearrangement could fita tandem duplication model. However, next-generation sequencing did not identify the breakpoint.

CONCLUSIONThe genetic etiology for three families affected with SHFM have been identified, which has provideda basis for genetic counseling and guidance for reproduction.

Chromosomes, Human, Pair 10 ; genetics ; Female ; Foot Deformities, Congenital ; genetics ; Genetic Testing ; Hand Deformities, Congenital ; genetics ; Humans ; Limb Deformities, Congenital ; genetics ; Male ; Mutation ; genetics ; Pedigree

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

OBJECTIVETo analyze the karyotypes and SRD5A2 gene mutations in 25 patients with sporadic or familial hypospadias.

METHODSThe patients included 10 adults and 15 children, whose chromosomes were analyzed by G-banded karyotyping, and the SRD5A2 genes were sequenced.

RESULTSTwo patients were found to have an abnormal karyotype, while eight have carried compound heterozygous mutations of the SRD5A2 gene, which included 5 genotypes formed by 6 types of mutations, i.e., p.G203S/p.R227Q, p.R227Q/p.R246Q, p.Q6X/p.Q71X, p.L20P/p.G203S, and p.Q71X/p.R227Q. Mutations of the SRD5A2 gene were present in 32% (8/25) of all patients, 35% (8/23) in those with a normal karyotype, and 44.4% (8/18) in those with proximal type hypospadia. Bioinformatic analysis, literature review and pedigree analysis confirmed that all such mutations are pathogenic.

CONCLUSIONChromosomal anomalies and mutations of the SRD5A2 gene are the main cause of hypospadias. Sequencing of the SRD5A2 gene may explain the etiology of nearly half of the patients with proximal type of hypospadas but a normal karyotype, which can facilitate genetic consulting.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase ; genetics ; metabolism ; Adolescent ; Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Child, Preschool ; Female ; Humans ; Hypospadias ; enzymology ; genetics ; Infant ; Infant, Newborn ; Karyotyping ; Male ; Membrane Proteins ; genetics ; metabolism ; Mutation ; Young Adult