Objective:To explore the clinical characteristics and genetic etiology of four children with Phelan-McDermid syndrome (PMS).Methods:Four children who had visited the Affiliated Women and Children′s Hospital of Ningbo University between June 2, 2022 and May 8, 2023 were selected as the study subjects. Clinical data of the children were collected. Genomic DNA was extracted from peripheral blood samples of the children and their parents and subjected to whole exome sequencing (WES). Candidate variants were verified by Sanger sequencing and quantitative PCR (q-PCR) analysis. This study was approved by the Medical Ethics Committee of the Affiliated Women and Children′s Hospital of Ningbo University (Ethics No. EC2020-048).Results:All children had presented with speech and language delays and intellectual disability. Children 3 and 4 also presented with autistic behaviors. WES showed that the children 1 and 2 had respectively carried a heterozygous c.731T>C (p.Leu244Pro) and a c.2782_2851del (p.Gly928ArgfsTer4) variant of the SHANK3 gene. Sanger sequencing confirmed that their parents did not carry the same variant, suggesting that they were de novo in origin. Children 3 and 4 had respectively harbored a 121 kb and 52.02 kb heterozygous deletion at chromosome 22q13.33, which had both encompassed the SHANK3 and ACR genes mapped to 22q13.33. q-PCR results showed that the deletion of SHANK3 and ACR genes were de novo in origin. Based on the guidelines from the American College of Medical Genetics and Genomics, the c. 731T>C and c. 2782_2851del variants were predicted to be likely pathogenic (PS2+ PM2_Supporting+ PP3) and pathogenic (PVS1+ PM2_Supporting+ PS2_Supporting), respectively. Furthermore, the 52.02 kb and 121 kb heterozygous deletions in 22q13.33 were both predicted to be pathogenic (2D+ 4C, 1.05 in score; 2D+ 4C, 1 in score). Conclusion:The four children were all diagnosed with PMS by genetic testing. Above finding has enriched the phenotypic and mutational spectrum of PMS, and provided a basis for clinical diagnosis and genetic counseling for their families.

Objective:To investigate the pathogenic spectrum of children with severe infection by metagenomic next generation sequencing (mNGS).Methods:This study was a cross-sectional study. We collected 212 cases of severely infected pediatric patients admitted to the Intensive Care Unit (ICU) of the Women and Children′s Hospital of Ningbo University from January 2022 to June 2023, and performed metagenomic next-generation sequencing (mNGS) on 249 samples to analyze the pathogenic distribution characteristics.Results:Among the 249 samples of 212 children, the positive detection rate was 49.80% (124/249), including 14 cases of mixed infections, accounting for 6.60% (14/212). According to the mNGS technology, the pathogen distribution of severely infected children showed that the most common Gram-positive bacteria were Staphylococcus aureus (3.61%, 9/249), Streptococcus pneumoniae (2.81%, 7/249), and Staphylococcus epidermidis (2.41%, 6/249); the most common Gram-negative bacteria were Klebsiella aerogenes (2.41%, 6/249), Klebsiella pneumoniae (2.41%, 6/249), and Haemophilus parainfluenzae (2.01%, 5/249). The most common fungus was Candida parapsilosis (2.01%, 5/249). The most common virus was Human Cytomegalovirus (HCMV) (6.02%, 15/249), Human Herpesvirus 1 (HHV-1) (1.61%, 4/249), and Epstein-Barr virus (EBV) (1.61%, 4/249). The most common atypical pathogen was Mycoplasma pneumoniae (3.21%, 8/249). Conclusions:This study explored the pathogen spectrum in severely infected pediatric patients through mNGS, contributing to the diagnosis of mixed infections or infections caused by uncommon or rare pathogens, which enables rapid and efficient identification of pathogens.

OBJECTIVE: To explore the clinical characteristics and genetic etiology for two children with Neurodevelopmental disorder with hypotonia, stereotypic hand movements, and impaired language (MEDHSIL). METHODS: Two children who had visited the Ningbo Women and Children's Hospital on October 15, 2021 were selected as the study subjects. Whole exome sequencing (WES) was carried out for both patients. Candidate variants were verified by Sanger sequencing of their family members. RESULTS: The two children were respectively found to harbor a heterozygous c.138delC (p.Ile47Serfs*42) variant and a c.833del (p.L278*) variant of the MEF2C gene. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were predicted to be pathogenic (PVS1+PS2+PM2_Supporting). CONCLUSION The c.138delC and c.833del variants of the MEF2C gene probably underlay the pathogenesis of MEDHSIL in the two children. Above findings have enriched the mutational spectrum of the MEF2C gene and enabled genetic counseling for their families.
Child ; Humans ; Family ; Genetic Counseling ; Language ; MEF2 Transcription Factors/genetics* ; Muscle Hypotonia/genetics* ; Neurodevelopmental Disorders

OBJECTIVE: To explore the types of NF1 gene variants and clinical characteristics among patients with Neurofibromatosis type I (NF1). METHODS: Clinical data of 12 patients diagnosed at Ningbo Women and Children's Hospital between December 2019 and May 2022 were retrospectively analyzed. The probands and their family members were subjected to high-throughput sequencing, and candidate variants were verified by Sanger sequencing and chromosome microarray analysis. RESULTS: The 12 patients had ranged from 4 months to 27 years old, with a male-to-female ratio of 2 : 1. Cafè-au-lait spots were found in all patients. 83.3% of them also had axillary and/or inguinal freckling, 58.3% had neurofibromas, and 16.7% had congenital pseudarthrosis of the tibia. Five types of NF1 gene variants were identified in the patients, including 5 nonsense variants, 4 frameshift variants, 1 missense variant, 1 splice variant, 1 large deletion involving the whole gene. Six patients were found to harbor de novo variants, 2 had inherited the variants from their parents, and 4 were not verified for their parental origin. The c.3379del (p.Thr1127Glnfs*15) and c.6628_6629del (p.Glu2210Thrfs*10) variants were unreported in literature and databases. CONCLUSION Most NF1 patients may present with Cafè-au-lait spots initially and are due to pathogenic variant of the NF1 gene. High-throughput sequencing can efficiently identify such variants among the patients and enable the definite diagnosis.
Child ; Humans ; Female ; Male ; Neurofibromatosis 1/diagnosis* ; Cafe-au-Lait Spots/diagnosis* ; Genes, Neurofibromatosis 1 ; Retrospective Studies ; Frameshift Mutation

OBJECTIVE: To assess the value of genetic screening by high-throughput sequencing (HTS) for the early diagnosis of neonatal diseases. METHODS: A total of 2 060 neonates born at Ningbo Women and Children's Hospital from March to September 2021 were selected as the study subjects. All neonates had undergone conventional tandem mass spectrometry metabolite analysis and fluorescent immunoassay analysis. HTS was carried out to detect the definite pathogenic variant sites with high-frequency of 135 disease-related genes. Candidate variants were verified by Sanger sequencing or multiplex ligation-dependent probe amplification (MLPA). RESULTS: Among the 2 060 newborns, 31 were diagnosed with genetic diseases, 557 were found to be carriers, and 1 472 were negative. Among the 31 neonates, 5 had G6PD, 19 had hereditary non-syndromic deafness due to variants of GJB2, GJB3 and MT-RNR1 genes, 2 had PAH gene variants, 1 had GAA gene variants, 1 had SMN1 gene variants, 2 had MTTL1 gene variants, and 1 had GH1 gene variants. Clinically, 1 child had Spinal muscular atrophy (SMA), 1 had Glycogen storage disease II, 2 had congenital deafness, and 5 had G6PD deficiency. One mother was diagnosed with SMA. No patient was detected by conventional tandem mass spectrometry. Conventional fluorescence immunoassay had revealed 5 cases of G6PD deficiency (all positive by genetic screening) and 2 cases of hypothyroidism (identified as carriers). The most common variants identified in this region have involved DUOX2 (3.93%), ATP7B (2.48%), SLC26A4 (2.38%), GJB2 (2.33%), PAH (2.09%) and SLC22A5 genes (2.09%). CONCLUSION Neonatal genetic screening has a wide range of detection and high detection rate, which can significantly improve the efficacy of newborn screening when combined with conventional screening and facilitate secondary prevention for the affected children, diagnosis of family members and genetic counseling for the carriers.
Child ; Infant, Newborn ; Humans ; Female ; Prospective Studies ; Connexins/genetics* ; Connexin 26/genetics* ; Glucosephosphate Dehydrogenase Deficiency ; Mutation ; Sulfate Transporters/genetics* ; DNA Mutational Analysis ; Genetic Testing/methods* ; Deafness/genetics* ; Neonatal Screening/methods* ; Hearing Loss, Sensorineural/genetics* ; High-Throughput Nucleotide Sequencing ; Solute Carrier Family 22 Member 5/genetics*

OBJECTIVE: To explore the clinical features and genomic abnorm ality of a fetus enlarged multicystic dysplastic kidneys with oligohydramnios caused by NPHP3 gene mutation. METHODS: The fetuse was found to have multicystic dysplastic kidneys with oligohydramnios upon ultrasonography during the second trimester. Following induced abortion, fetal tissue was collected for the extraction of DNA, chromosomal microarray analysis (CMA) and whole exome sequencing (WES). Sanger sequencing was used to verify the suspected variants in the family. RESULTS: Antenatal ultrasound examination at 19 weeks showed "polycystic" kidneys with Oligohydramnios. Delivery was by induced labour because of the critically low amniotic fluid volume. Testing of CMA was normal. WES showed a compound heterozygous mutation of c.1817G>A, p.W606X; c.432dupA, p.E145Rfs*18 mutations are novel mutations in this study. CONCLUSION The research may further expand the NPHP3 gene mutation spectrum. Enlarged multicystic dysplastic kidneys with oligohydramnios caused by NPHP3 gene mutation at least include one or two splice site mutation, frameshift mutation or nonsense mutation foetal poor prognosis.
Amniotic Fluid ; Female ; Humans ; Kidney Diseases, Cystic ; Multicystic Dysplastic Kidney/genetics* ; Mutation ; Oligohydramnios/genetics* ; Polycystic Kidney Diseases ; Pregnancy ; Ultrasonography, Prenatal

OBJECTIVE: Through a retrospective large sample analysis of copy number variants in single center, we explored the technical standards for the interpretation and reporting of constitutional copy-number variants (CNVs) jointly proposed by the American College of Medical Genetics and Genomics (ACMG) and the Clinical Genome Resource (ClinGen) in 2019, analyzing its impact on CNVs ratings and the improvement in the consistency of the classification of CNVs in clinical laboratories. METHODS: 236 CNVs that assessed as pathogenic, uncertain significant (including likely pathogenic, uncertain and likely benign) by the 2011 ACMG guidelines between August 2018 and December 2019 in our center were re-analyzed. Four working group members of the center reclassified and evaluated 235 CNVs according to 2019 ACMG guidelines. RESULTS: The consistency of clinical significance classification of CNVs was 91% and the α test coefficient was 0.98 among four working group members. Compared with the 2011 and 2019 ACMG technical standards for the CNVs classification, evaluation of pathogenicity and uncertain significant is basically consistent. 90% (45/50) of likely pathogenic and likely benign CNVs were Re-evaluated as variants of uncertain significance, and the difference is significant. CONCLUSION The new version ACMG/ClinGen guidelines for the evaluation of CNVs developed semi-quantitative point-based scoring system and help to improve the consistency in clinical classifications. It can also make the interpretation of CNVs more standardized and transparent.
DNA Copy Number Variations ; Genetic Testing ; Genetic Variation ; Genome, Human ; Humans ; Mutation ; Retrospective Studies

OBJECTIVE: To explore the clinical phenotype and genetic basis for a fetus suspected for Coffin-Siris syndrome. METHODS: Chromosomal microarray analysis (CMA) and whole exome sequencing (WES) were carried out for the fetus. Candidate variant was verified by Sanger sequencing. RESULTS: Prenatal ultrasound at 23rd gestational week has revealed fetal ventriculomegaly. No abnormality was found by CMA, while WES revealed that the fetus has harbored a de novo heterozygous c.2851G>A (p.G951R) variant of the SMARCA4 gene, which was predicted to be pathogenic. CONCLUSION Genetic testing should be considered for fetuses featuring progressive widening of lateral cerebral ventricles.
Female ; Humans ; Pregnancy ; DNA Helicases/genetics* ; Fetus ; Genetic Testing ; Nuclear Proteins/genetics* ; Phenotype ; Transcription Factors/genetics* ; Exome Sequencing

OBJECTIVE: To reported on two fetuses diagnosed with 17q12 microdeletion syndrome. METHODS: The two fetuses were respectively found to have renal abnormalities and polyhydramnios upon second and third trimester ultrasonography. Umbilical cord blood of the first fetus and amniotic fluid of the second fetus were subjected to single nucleotide polymorphism array (SNP-array) analysis. After 17q12 microdeletion was found in the first fetus, SNP-array was carried out on peripheral blood samples of the parents to determine its origin. With the medical history of the parents taken into consideration, the father underwent high-throughput sequencing for 565 urinary system-related genes to exclude pathogenic or likely pathogenic variants associated with congenital malformations of the urinary and reproductive systems. RESULTS: In both fetuses, SNP-array has revealed a 1.42 Mb deletion at 17q12, or arr[hg19]17q12 (34 822 465-36 243 365) × 1. In both cases the microdeletion was inherited from the father, in whom no urinary disease-related pathogenic or likely pathogenic variants was identified. CONCLUSION Paternally derived 17q12 microdeletions probably underlay the genetic etiology of the two fetuses with renal ultrasound abnormalities and polyhydramnios. SNP-array can enable the diagnosis and facilitate genetic counseling and prenatal diagnosis for the families.
Chromosome Deletion ; Chromosome Disorders ; Chromosomes, Human, Pair 17 ; Female ; Fetus ; Genetic Counseling ; Genetic Testing ; Humans ; Polyhydramnios/genetics* ; Pregnancy ; Prenatal Diagnosis

OBJECTIVE: To establish a newborn screening system for Duchenne muscular dystrophy (DMD) through assessment of MM isoenzyme of creatine kinase (CK-MM) activity. METHODS: The CK-MM level was detected using dry blood spot filter paper from 10 252 male newborns. The results were grouped based on their gestational age, sampling time and intervals between the experiments. The threshold value for CK-MM necessitating genetic testing was determined. Next-generation sequencing (NGS) was carried out for those with a CK-MM value over the threshold, and the result was verified by multiplex ligation-dependent probe amplification (MLPA). RESULTS: Based on the result of non-parametric rank sum test, the median CK-MM concentration has increased with the gestational age, and was inversely correlated with the age of the newborns among unaffected specimens. CK-MM on dry blood spot filter paper can be stable for 14 days at 2-8℃. Statistical analysis of CK-MM value of the 10 252 neonates suggested that the threshold may be set as 700 ng/mL. Exonic deletions were found in 2 confirmed cases, whose CK-MM level was greater than 2000 ng/mL. CONCLUSION Detection of CK-MM in dry blood spot filter paper has provided an effective method for newborn screening of DMD. This simple and inexpensive method can be used for large-scale screening, which is of great value to the early intervention and treatment of the disease.
Dystrophin/genetics* ; Exons ; Humans ; Infant, Newborn ; Male ; Multiplex Polymerase Chain Reaction ; Muscular Dystrophy, Duchenne/genetics* ; Neonatal Screening