OBJECTIVE: To explore the efficacy of a Thalassemia risk assessment software for the screening of thalassemia mutation carriers and distribution of thalassemia genotypes detected by screening. METHODS: A total of 6 040 individuals were evaluated at Leshan Maternal and Child Health Care Hospital between 2022 and 2024 using the commonly used clinical thalassemia risk assessment method and the thalassemia screening software, respectively, and the performance indicators of the two methods were compared and analyzed against the result of thalassemia gene testing. This study was approved by the Ethics Committee of our hospital (Ethics No.: LfyLL[2022]005). RESULTS: The high-risk rate by the thalassemia screening software was 11.19%, with a sensitivity of 95.12%, specificity of 93.28%, positive predictive value of 43.20%, negative predictive value of 99.72%, and the area under the ROC curve (AUC) was 0.942. The thalassemia gene detection rate of the high-risk samples screened was 4.83%. The high-risk screening rate of the conventional method was 2.50%, with a sensitivity of 51.22%, specificity of 93.28%, positive predictive value of 80.79%, negative predictive value of 97.40%, and the AUC was 0.754. The thalassemia gene detection rate of the high-risk samples was 2.02%. CONCLUSION The software can effectively detect thalassemia carriers and significantly reduce the missed detection compared with conventional method, thereby significantly improve the efficacy of screening.
Humans ; Thalassemia/diagnosis* ; Software ; Female ; Genetic Testing/methods* ; Male ; Mutation ; Adult ; Genotype ; ROC Curve ; Risk Assessment

OBJECTIVE: To assess the feasibility of first polar body transfer (PB1T) combined with preimplantation mitochondrial genetic testing for blocking the transmission of a pathogenic mitochondrial DNA 8993T>G mutation. METHODS: A Chinese family affected with Leigh syndrome which had attended the Reproductive Medicine Centre of the First Affiliated Hospital of Anhui Medical University in September 2021 was selected as the study subject. Controlled ovarian hyperstimulation was carried out for the proband after completing the detection of the mitochondrial DNA 8993T>G mutation load among the pedigree members. Mature MII oocytes were inseminated by intracytoplasmic sperm injection (ICSI), cultured in vitro for 5 to 6 days to the blastocyst stage, and trophoblastocytes were obtained by microbiopsy. Mitochondrial DNA testing (PGT-MT) and chromosomal aneuploidy (PGT-A) analyses were carried out after whole-genome amplification, and the embryos with zero mutation load were selected for transfer. Amniotic fluid and umbilical cord blood samples were collected during middle pregnancy and after birth respectively for mitochondrial DNA testing to verify the reliability of embryo screening. As an attempt, PB1 with good morphology of MII oocytes was selected for transfer into the enucleated oocytoplasm from healthy donors, followed by ICSI fertilization, blastocyst culture and PGT of embryos using the same procedure. This study has been approved by the Ethics Committee of the First Affiliated Hospital of Anhui Medical University (No. 2021zhyx-B12). RESULTS: An antagonist protocol was used for ovarian stimulation, and a total of 19 oocytes were obtained, of which 14 MII were fertilized by ICSI, and 2 had developed into blastocysts. PGT-MT was carried out on biopsied trophoblastocytes, in which the mitochondrial DNA 8993T>G mutation load was not detected in one embryo, the other was 100% mutated, and the mutation loads of the remaining unfertilized eggs and developmentally arrested embryos ranged from 0% ~ 100%, presenting a clear biased distribution. With fully informed consent, one PGT-MT zero mutation load blastocyst was transferred and clinical pregnancy was achieved. Mitochondrial DNA and chromosomal testing of amniotic fluid cells during middle pregnancy had revealed no abnormalities. The proband had delivered a healthy boy through Caesarean section at 39⁺⁵ weeks of gestation, and no mutation was detected in the cord blood sample. Five well-formed PBs from 14 eggs were selected for PB1 transfer, followed by ICSI and culture, and two of the reconstituted embryos had formed blastocysts, with none of the above mutations detected in the biopsied samples. CONCLUSION The PGT-MT technology can help families affected with mitochondrial diseases to have healthy offspring. PB1 transfer in combination with ICSI and PGT-MT holds the promise of turning waste into treasure and providing an alternative means of fertility for such families.
Humans ; Preimplantation Diagnosis/methods* ; Female ; DNA, Mitochondrial/genetics* ; Genetic Testing/methods* ; Pregnancy ; Mitochondrial Diseases/genetics* ; Polar Bodies ; Adult ; Feasibility Studies ; Sperm Injections, Intracytoplasmic/methods* ; Embryo Transfer/methods* ; Mutation ; Male ; Blastocyst/metabolism* ; Pedigree

OBJECTIVE: To explore the results of four types of Urea cycle disorders (UCDs) in newborns from the Xuzhou region, assess the efficacy of newborn screening by tandem mass spectrometry (MS/MS), and analyze their genetic characteristics. METHODS: A retrospective analysis was performed using tandem mass spectrometry to screen for inherited metabolic disorders in 691 712 newborns at the Maternal and Child Health Care Hospital of Xuzhou from November 2015 to December 2023. Ten children (cases 1-10) were diagnosed with Ornithine transcarbamylase deficiency (OTCD), Carbamoylphosphate synthase 1 deficiency (CPS1D), Arginase deficiency (ARGD), and Argininosuccinate synthase deficiency (ASSD) based on MS/MS and genetic testing. This study was approved by the Medical Ethics Committee of Xuzhou Maternity and Child Health Care Hospital (Ethics No.XZFY2024-051K-01J). RESULTS: A total of 691 712 neonates were screened for UCDs using MS/MS, which identified 1 237, 1 237, 510, and 1 009 initial positive cases for OTCD, CPS1D, ASSD, and ARGD, respectively. After genetic testing, 1 case of OTCD, 1 case of CPS1D, 1 case of ASSD, and 7 cases of ARGD were confirmed. The overall positive predictive value for these four UCDs was 0.362%. Among the 10 diagnosed UCD cases, four novel variants were identified, which included OTC: c.1024C>A (p.L342M) and ASS1: c.826A>G (p.M276V), c.695C>T (p.P232L) and c.694C>T (p.P232S). Bioinformatic analysis has rated these as variants of uncertain clinical significance or likely pathogenic based on guidelines from the American College of Medical Genetics and Genomics (ACMG). CONCLUSION The incidence of four UCDs in neonates from the Xuzhou area is relatively low, and there is a correlation between genetic variants and clinical phenotypes. For novel variants with uncertain clinical significance or suspected pathogenicity, their pathogenicity should be clarified in conjunction with clinical and biochemical indicators. The four novel pathogenic variants of UCDs identified in this study have enriched the mutational spectrum of UCDs-associated genes in the Xuzhou region.
Humans ; Infant, Newborn ; Tandem Mass Spectrometry/methods* ; Urea Cycle Disorders, Inborn/diagnosis* ; Neonatal Screening/methods* ; Genetic Testing/methods* ; Female ; Retrospective Studies ; Male ; Ornithine Carbamoyltransferase Deficiency Disease/diagnosis* ; Mutation ; Carbamoyl-Phosphate Synthase (Ammonia)/genetics* ; Ornithine Carbamoyltransferase/genetics*

OBJECTIVE: To explore the clinical features and genetic characteristics of three patients with Infantile liver failure syndrome type 2 (ILFS2). METHODS: Three children who were diagnosed with ILFS2 at the Children's Hospital Affiliated to Zhengzhou University from February 2023 to February 2024 were selected as the study subjects. Clinical data of the children were collected. Peripheral blood samples of the children and their parents were collected and subjected to whole exome sequencing (WES). Candidate variants of the NBAS gene were verified by Sanger sequencing. This study was approved by the Ethics Committee of the Children's Hospital Affiliated to Zhengzhou University (Ethics No. 2024-k-069). RESULTS: The three children had presented with fever-triggered recurrent acute liver failure. All of them were found to harbor compound heterozygous variants of the NBAS gene, including c.3596G>A and c.1181A>T in child 1, c.2617C>T and c.2T>C in child 2, and c.3596G>A and c.2817_2818insT in child 3. Among these, the c.1181A>T and c.2817_2818insT variants were unreported previously. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), they were respectively classified as variants of uncertain significance (PM2_Supporting+PM3+PP3) and pathogenic (PVS1+PM2_Supporting+PM3). CONCLUSION Combined with the patient's clinical phenotype, the compound heterozygous variants of the NBAS gene probably underlay the pathogenesis of ILFS2 in the three children. For children with fever-related acute liver failure of unknown causes, the possibility of this disease should be suspected, and genetic testing may facilitate the diagnosis. Early diagnosis and timely intervention can significantly improve the prognosis. Discoveries of the c.1181A>T and c.2817_2818insT variants have enriched the mutational spectrum of the NBAS gene.
Humans ; Exome Sequencing ; Genetic Testing/methods* ; Liver Failure, Acute/etiology* ; Mutation ; Child ; Adult ; Neoplasm Proteins

OBJECTIVE: To investigate the clinical features and genetic variants associated with Multiple mitochondrial dysfunction syndrome (MMDS) type 3 in two children. METHODS: Two children diagnosed with MMDS type 3 at Zhuhai Maternal and Child Health Care Hospital in January 2021 were selected for this study. A retrospective analysis of their clinical data was carried out. Whole exome sequencing was conducted on the two children and their parents, followed by Sanger sequencing for candidate variants and bioinformatic analysis. Both children received comprehensive rehabilitative therapy and were followed up for 3 years. This study was approved by the Ethics Committee of Zhuhai Maternal and Child Health Hospital (Ethics No. 202380). RESULTS: The two MMDS type 3 children were monozygotic twin girls, aged 9 months, presenting with developmental regression, pyramidal signs, and other clinical manifestations. Cranial MRI revealed widespread abnormal signals and vacuolar changes in the white matter. Whole exome sequencing revealed that both children had harbored compound heterozygous variants of the IBA57 gene, namely c.286T>C (p.Tyr96His) and c.307C>T (p.Gln103Ter). Sanger sequencing confirmed that these variants were inherited from their father and mother, respectively. According to the American College of Medical Genetics and Genomics (ACMG) guidelines, both variants were classified as pathogenic (PM2_Supporting+PM3_Very Strong+PP3_Moderate; PVS1+PM2_Supporting+PM3). After treatment with vitamins, levocarnitine, ATP, coenzyme Q10, and other drugs, both children showed partial recovery of neurodevelopmental regression, with improvement in feeding and sleep. Over the 3-year follow-up, there was slow but progressive improvement in motor, language, and cognitive development. CONCLUSION The compound heterozygous variants c.286T>C (p.Tyr96His) and c.307C>T (p.Gln103Ter) of the IBA57 gene probably underlay the MMDS type 3 in the twin pair. Clinicians should be vigilant about the possibility of MMDS type 3 in children with neurodevelopmental regression and early cranial MRI findings indicating widespread white matter abnormalities with vacuolar changes, as these may be indicative of IBA57 gene variants.
Female ; Humans ; Infant ; Calcium-Binding Proteins/genetics* ; Exome Sequencing ; Genetic Testing/methods* ; Microfilament Proteins/genetics* ; Mitochondrial Diseases/genetics* ; Mutation ; Retrospective Studies ; Carrier Proteins

OBJECTIVE: To explore the genotype-phenotype correlation in a Charcot-Marie-Tooth type 2A2A (CMT2A2A) pedigree and to provide genetic counseling for its subsequent pregnancies. METHODS: A Chinese pedigree presenting with "lower limb muscle atrophy and movement disorders" at the Prenatal Diagnosis Center of Xuzhou Central Hospital between January and August 2024 was selected as the study subject. Relevant clinical data were collected from the pedigree members. Peripheral blood samples from affected individuals, and amniotic fluid and/or chorionic villus samples were obtained for DNA extraction. Whole exome sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing. Pathogenicity assessment and bioinformatic analysis were conducted. This study was approved by the Medical Ethics Committee of Xuzhou Central Hospital (Ethics No. XZXY-LK-20240111-0019). RESULTS: All affected individuals in this pedigree were females, whom included the proband, her mother, and her first daughter. Earlier age of onset was associated with more severe lower limb atrophy. A heterozygous missense variant of the MFN2 gene, namely c.314C>T (p.Thr105Met), was identified in the proband, her mother, daughter, and the third fetus from a re-marriage. The same variant was absent in her elder brother, current husband, and her fourth fetus. Based on the guidelines from American College of Medical Genetics and Genomics (ACMG) and recommendations from Clinical Genome Resources (ClinGen), the variant was classified as pathogenic (PP1_Strong+PM1+PS3+PS4_Moderate+PP3_Moderate+PM2_Supporting). Analyses with PROVEAN and Mutation Taster had categorized the variant as "deleterious" and "disease-causing", respectively. Analysis with Uniprot and Jalview showed that the affected amino acid residue is conserved across multiple species. ChEBI software predicted that the variant may alter the polarity of the 105th amino acid residue. CONCLUSION The c.314C>T (p.Thr105Met) missense variant of the MFN2 gene probably underlie the CMT2A2A in this pedigree. Above finding has enabled prenatal diagnosis and genetic counseling for its subsequent pregnancies.
Adult ; Female ; Humans ; Male ; Charcot-Marie-Tooth Disease/genetics* ; East Asian People/genetics* ; Exome Sequencing ; Genetic Testing/methods* ; GTP Phosphohydrolases/genetics* ; Mitochondrial Proteins/genetics* ; Mutation, Missense ; Pedigree

OBJECTIVE: To assess the carrier frequency of spinal muscular atrophy (SMA) in women of childbearing age in Chongqing and to evaluate prenatal diagnostic outcomes in high-risk couples. METHODS: A total of 17 926 women of childbearing age attending Chongqing Health Center for Women and Children between May 2021 and November 2023 were enrolled, including 3 398 pre-pregnant women and 14 528 pregnant women, all of whom had no clinical phenotype or family history of SMA or related neuromuscular disorders. Real-time quantitative PCR (RT-qPCR) was used to determine the copy number variations in exons 7 and 8 (E7, E8) of the SMN1 gene. High-risk carriers were identified based on the genetic screening results. Multiplex ligation-dependent probe amplification (MLPA) was employed for prenatal diagnosis of fetuses from high-risk couples. This study was approved by the Medical Ethics Committee of Chongqing Health Center for Women and Children (Ethics No.2021-RGI-02). RESULTS: Among the 17 926 women of childbearing age, 298 (1.66%) were identified as heterozygous carriers, including 278 (1.55%) with concurrent deletions of E7 and E8, and 20 (0.11%) with isolated deletions of E7. Seven high-risk couples were identified, six of whom were prenatal couples. Of the two fetuses from these high-risk pregnancies, both exhibited heterozygous deletions of E7 and E8 in the SMN1 gene, while four fetuses showed no abnormalities. CONCLUSION This study provides a comprehensive assessment of the carrier frequency of SMA among women of childbearing age in Chongqing, offering valuable data for the primary and secondary prevention of SMA-related birth defects in the region.
Humans ; Female ; Muscular Atrophy, Spinal/diagnosis* ; Pregnancy ; Prenatal Diagnosis/methods* ; Adult ; Survival of Motor Neuron 1 Protein/genetics* ; Genetic Carrier Screening/methods* ; DNA Copy Number Variations/genetics* ; China ; Genetic Testing ; Heterozygote

OBJECTIVE: To provide preimplantation genetic testing (PGT) for a patient with Incontinentia pigmenti (IP) due to IKBKG gene variant but without family samples through construction of single nucleotide polymorphism (SNP)-based haplotype by Long-read sequencing (LRS) technology. METHODS: A female IP patient with a heterozygous IKBKG c.1167dup variant but without family genetic data who sought genetic counseling at Women and Children' Hospital of Ningbo University in November 2021 was selected as the study subject. The IKBKG gene has a highly homologous pseudogene IKBKGP1. Genomic DNA was extracted from peripheral blood samples from the couple, and LRS was used to obtain informative SNP loci flanking the variant locus, enabling the construction of SNP haplotype with a long segment spanning from the non-homologous region of IKBKG to the variant site. Trophoblast cells were biopsied from blastocysts fertilized through intracytoplasmic sperm injection, and next-generation sequencing (NGS) was used to determine the SNP information of the embryos. Linkage analysis with the parental SNP haplotypes was conducted to detect the carrier status of the embryos and exclude chromosomal aneuploidies. Sanger sequencing was carried out to validate the result. A euploid embryo without the pathogenic variant was selected for transfer. Prenatal diagnosis was carried out by amniocentesis at mid-trimester to verify the result of PGT tests, and follow-up was conducted after the baby was born. This study has been approved by the Ethics Committee of Women and Children's Hospital of Ningbo University (Ethics No. EC2023-094). RESULTS: A total of seven blastocysts were tested, and PGT results indicated that two embryos were euploid and did not carry the pathogenic variant. One euploid embryo was transferred, which resulted in a singleton pregnancy. Amniocentesis at 24 weeks of gestation confirmed that the status of fetal IKBKG gene, and its chromosomal status was consistent with the PGT results. A healthy male infant was born at 38+6 weeks of gestation. CONCLUSION For IP patients with de novo mutation or without family genetic samples, PGT with LRS can directly construct the SNP-based haplotype while avoiding interference from pseudogenes, providing an effective strategy for PGT.
Female ; Humans ; Male ; Pregnancy ; Genetic Testing/methods* ; Haplotypes/genetics* ; High-Throughput Nucleotide Sequencing/methods* ; I-kappa B Kinase/genetics* ; Incontinentia Pigmenti/diagnosis* ; Polymorphism, Single Nucleotide/genetics* ; Preimplantation Diagnosis/methods* ; Infant, Newborn

OBJECTIVE: To assess the diagnostic value of whole exome sequencing (WES) for fetuses undergone induced abortion due to structural abnormalities. METHODS: A retrospective analysis was carried out on 43 aborted fetuses with negative results for copy number variation (CNV) testing from January 2023 to June 2024 at Northwest Women's and Children's Hospital. Trio-WES was carried out on the tissues from the aborted fetuses. This study has been approved by the Ethics Committee of the Hospital (Ethics No. 21-036). RESULTS: Among the 43 abortic fetuses, WES has detected pathogenic variants in 15 cases, with a total of 9 pathogenic variants, 5 suspected pathogenic variants, and 5 variants of uncertain significance. No definite pathogenic variants were detected in the remaining 28 cases. CONCLUSION For fetuses with structural abnormalities and negative results from CNV testing, WES can increase the diagnostic rate and facilitate etiological diagnosis and genetic counseling.
Humans ; Female ; Exome Sequencing/methods* ; Pregnancy ; DNA Copy Number Variations/genetics* ; Retrospective Studies ; Adult ; Prenatal Diagnosis/methods* ; Abortion, Induced ; Fetus/abnormalities* ; Congenital Abnormalities/diagnosis* ; Genetic Testing ; Aborted Fetus/abnormalities*

OBJECTIVE: To assess the value of whole exome sequencing (WES) for the diagnosis of early-onset genetic diseases among infants aged 0 to 6 month in Ningbo region. METHODS: 268 infants presented at the Women and Children's Hospital Affiliated to Ningbo University from January 2022 to June 2024 undergoing WES-based genetic testing were enrolled. Peripheral blood samples were collected from the infants and their parents and subjected to WES. Pathogenic variants were identified by clinical manifestations. This study has been approved by the Medical Ethics Committee of the Hospital (Ethics No. EC2023-017). RESULTS: Among the 268 infants, 124 (46.3%) had phenotype-explaining genetic variants. For 42 family-based WES tests, 20 (47.62%) were abnormal, whilst in 226 single-person WES tests, 104 (46.02%) had abnormalities, with 76 (33.63%) verified by parental testing. In 96 fully family-verified cases, 31 were de novo, 40 were parent-inherited, 25 were single-parent-inherited. These included 35 inborn metabolic errors, 28 rare syndromes, 9 neurodevelopmental disorders, 4 musculoskeletal diseases, 5 congenital deafness, 2 mitochondrial diseases, 4 endocrine diseases, and 9 others. Among these, there were 7 pathogenic copy number variations (all deletions), 3 chromosomal abnormalities, and 85 single-nucleotide variations. One case of Beckwith-Wiedemann syndrome was detected by methylation MLPA. Among the single-nucleotide variants, 114 pathogenic/likely pathogenic variants were identified in 61 genes, with common ones including missense variants (64.04%), frameshifting variants (20.18%) and splicing variants (4.39%). CONCLUSION WES can offer effective diagnosis for hereditary diseases with specific/non-specific manifestations. For early-age infants, higher detection rates may be attained for inborn metabolic errors, rare syndromes, neurodevelopmental disorders, congenital deafness, and musculoskeletal diseases. Compared with single-person WES, family-based WES can attain a higher diagnostic efficiency.
Humans ; Exome Sequencing/methods* ; Infant ; Female ; Male ; Infant, Newborn ; Genetic Diseases, Inborn/diagnosis* ; Genetic Testing/methods*