Objective:To investigate the clinical value of targeted sequencing panel in the detection of genetic variation in neonates in neonatal intensive care unit (NICU).Methods:All neonates (≤28 d of age) admitted in the NICU (case group) and 200 full-term healthy neonates born with no obvious phenotypic abnormalities of Huzhou Maternity and Child Health Care Hospital were enrolled in this prospective study from November 2022 to January 2023. Based on a list of preventable and treatable rare diseases as well as newly screened diseases in China, a targeted sequencing panel suitable for Chinese newborns was designed to target the pathogenic genes and mutation sites associated with 601 genes and 542 diseases. Dried blood spot specimens were prepared and analyzed by the targeted sequencing panel. Pathogenic sites detected by the panel sequencing were verified using Sanger sequencing. The genetic testing results were analyzed according to the clinical features of the neonates. According to the number of primary clinical diagnosis index (including premature infants, neonatal hyperbilirubinemia, hemorrhagic diseases, neonatal infections, ventricular septal defect/patent ductus arteriosus, and others), these patients were divided into four groups with 1, 2, 3, and ≥4 diagnosis index, respectively. Chi-square test and linear correlation Chi-square test were used for statistical analysis. Results:There were 173 patients in the case group and 30.6% (53/173) of them carried pathogenic variants, including 52 positive for pathogenic genes and one with chromosome copy number variant. The positive rate of pathogenic genes was significantly higher in the case group than in the control group [30.1% (52/173) vs. 15.0% (30/200), χ 2=12.26, P<0.001]. Fourteen pathogenic genes were detected in the case group, including FLG, UGT1A1, G6PD, MYH7, AR, ABCC2, ACADS, CYP21A2, GJB2, MEFV, PAH, PKHD1, SCN4A, and HBA. In the case group, the detection rate of pathogenic variants in jaundiced neonates was higher than that in non-jaundiced neonates [35.2% (44/125) vs. 18.8% (9/48), χ 2=4.42, P=0.036]. However, there were no statistically significant differences in the detection rates of pathogenic variants between male and female infants, infants born to mothers of advanced maternal age or not, infants born to mothers with or without gestational diabetes mellitus, premature and term infants, or infants with or without hemorrhagic disorders, neonatal infections, or ventricular septal defects/patent ductus arteriosus in the case group (all P>0.05). The detection rate of pathogenic variants showed a linear increase in infants with 1, 2, 3, and ≥4 diagnosis index [21.1% (8/38), 25.4% (15/59), 38.2% (13/34), and 40.5% (17/42); linear correlation χ 2=4.84, P=0.028]. In the case group, seven genes with a high detection rate of genetic variation (including positive pathogenic genes and carriers) were UGT1A1 [had the highest detection rate, 24.9% (43/173)], GJB2, FLG, DUOX2, ABCA4, G6PD, and MUT. Seven loci with higher mutation frequency were c.211G>A(p.Gly71Arg), c.1091C>T(p.Pro364Leu), c.-41_-40dupTA, and c.686C>A(p.Pro229Gln) in the UGT1A1 gene, c.109G>A(p.Val37Ile) in the GJB2 gene, and c.12064A>T(p.Lys4022Ter) and c.3321del(p.Gly1109GlufsTer13) in the FLG gene. Conclusion:This panel sequencing can provide effective genetic testing for neonates in NICU, especially in children with complex clinical diagnosis.

Objective:To analyze the types and distribution of pathogenic variants for neonatal genetic diseases in Huzhou, Zhejiang Province.Methods:One thousand neonates (48 ~ 42 h after birth) born to Huzhou region were selected as the study subjects. Dry blood spot samples were collected from the newborns, and targeted capture high-throughput sequencing was carried out for pathogenic genes underlying 542 inherited diseases. Candidate variants were verified by Sanger sequencing.Results:Among the 1 000 newborns, the male to female ratio was 1.02 : 1.00. No pathogenic variants were detected in 253 cases, whilst 747 cases were found to carry at least one pathogenic variant, which yielded a carrier rate of 74.7%. The most frequently involved pathogenic gene was FLG, followed by GJB2, UGT1A1, USH2A and DUOX2. The variants were classified as homozygous, compound heterozygous, and hemizygous variants. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), 213 neonates were verified to have carried pathogenic and/or likely pathogenic variants, with a positive rate of 21.3%. The most commonly involved genes had included UGT1A1, FLG, GJB2, MEFV and G6PD. Conclusion:Newborn screening based on high-throughput sequencing technology can expand the scope of screening and improve the positive predictive value. Genetic counseling based on the results can improve the patients′ medical care and reduce neonatal mortality and childhood morbidity, while provide assistance to family members′ health management and reproductive decisions.

Objective:To explore the genetic basis for a child with mental retardation.Methods:The child was subjected to chromosomal microarray analysis (CMA) and targeted capture next-generation sequencing for the exons of genes related to genetic and metabolic diseases. Candidate variants were verified by Sanger sequencing of the child and his parents.Results:CMA suggested that the child has a 47, XYY karyotype. Next-generation sequencing revealed that the child has harbored compound heterozygous variants of the AUH gene, including c. 677G>A (p.R226H) and c. 373C>T (p.R125W), which were respectively inherited from his parents. Based on the American college of Medical Genetics and Genomics (ACMG) standards and guidelines, the c. 677G>A (P.r226h) variant was predicted as variant of uncertain significance (PM2+ PP4+ PP3), whilst the c. 373C>T (P.R125W) variant was predicted as likely pathogenic (PM1+ PM2+ PP3+ PP4). Conclusion:The child had XYY syndrome in conjunct with 3-methylglutaenedioic aciduria type I due to biallelic pathogenic variants of the AUH gene.

OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) to verify a fetus with partial 18p deletion signaled by non-invasive prenatal testing. METHODS: G-banding chromosomal karyotyping analysis was carried out on amniotic fluid sample of the fetus and peripheral blood samples from the parents. Amniotic DNA was also subjected to CMA analysis. The fetus was also subjected to systematic ultrasound scan. RESULTS: The fetus was found to have a karyotype of 46,XX,18p+. CMA has revealed a 5 Mb deletion at 18p11.32-p11.31, a 2.9 Mb duplication at 18p11.31-p11.23, and a 2.5 Mb duplication at 18p11.23-p11.22. No chromosomal aberration or microdeletion/microduplication was detected in either parent. CONCLUSION Non-invasive prenatal testing and CMA are both sensitive for the detection of chromosomal microdeletions and microduplications. CMA can help with clarification of genotype-phenotype correlation and facilitate prenatal diagnosis and genetic counseling for the family.
Chromosome Deletion ; Chromosomes ; Female ; Fetus ; Humans ; Karyotyping ; Pregnancy ; Prenatal Diagnosis

OBJECTIVE: To detect pathogenic variant in a child featuring Usher syndrome type II. METHODS: Peripheral blood samples of the child and his parents were collected for the analysis of variants of hearing impairment-related genes. The findings were verified in 100 individuals with normal hearing. RESULTS: The child was found to harbor compound heterozygous variants of the USH2A gene, namely c.8224-1G>C in intron 41 and c.5678C>G(p.Ser1893X) in exon 28, which were inherited respectively from his mother and father. Based on the American College of Medical Genetics and Genomics standards and guidelines, both c.8224-1G>C and c.5678C>G(p.Ser1893X) variants of USH2A gene were predicted to be pathogenic(PVS1+PM2+PM3). CONCLUSION The compound heterozygous variants c.8224-1G>C and c.5678C>G of the USH2A gene probably underlay the disease in this child. Above finding has enriched the spectrum of USH2A gene variants.
Child ; Exons ; Extracellular Matrix Proteins/genetics* ; Family ; Humans ; Introns ; United States ; Usher Syndromes/genetics*

OBJECTIVE: To explore the genetic basis for a child with global developmental delay and neurofibromatosis type 1 (NF1). METHODS: The patient underwent clinical examination. Whole exome sequencing (WES) was carried out to detect pathogenic genetic variants. RESULTS: The child had cafe au lait spots all over her body, pigmentation in the back, and global developmental delay as assessed by Gese II. Cranial MRI revealed globular abnormal density in the lower hemisphere of left posterior cranial fossa. WES detected a novel variant of the NF1 gene, c.6513-6515del (p.Tyr2171), which was strongly correlated with her clinical phenotype. The same variant was not found in either parent and was unreported previously. CONCLUSION The c.3842T>G variant of the NF1 gene probably underlay the NF1 and global developmental delay in this child, for whom prompt symptomatic treatment and regular follow-up were recommended.

OBJECTIVE: To explore the origin and mechanism of small supernumerary marker chromosomes (sSMC) in three fetuses. METHODS: The three fetuses were predicted to have carried chromosomal abnormalities by non-invasive prenatal testing (NIPT). G-banding chromosomal karyotyping analysis were carried out on amniotic fluid samples of the fetuses and peripheral blood samples from their parents. Single nucleotide polymorphism array (SNP-array) was used to determine the origin, size and genetic effect of sSMCs. RESULTS: In fetus 1, SNP array has detected two microduplications respectively at 4p16.3p15.2 (24.7 Mb) and 18p11.32q11.2 (20.5 Mb) which, as verified by fluorescence in situ hybridization (FISH), have derived from a balanced 46,XY,t(4;18)(p15.2q11.2) translocation carried by its father. Fetus 2 has carried a de novo microduplication of 15q11.2-q13.3 (9.7 Mb). The sequence of SMC in fetus 3 has derived from 21q11.2-q21.1 (8.3 Mb), which was inherited from its mother. CONCLUSION Both NIPT and SNP-array are highly accurate for the detection of sSMC. SNP-array can delineate the origin and size of abnormal chromosomes, which in turn can help with clarification of sSMC-related genotype-phenotype correlation and facilitate prenatal diagnosis and genetic counseling for the family.
Chromosome Duplication/genetics* ; Female ; Fetus ; Humans ; In Situ Hybridization, Fluorescence ; Male ; Polymorphism, Single Nucleotide ; Pregnancy ; Prenatal Diagnosis ; Translocation, Genetic/genetics*

TORCH, which is considered as a series of pathogens, including the Toxoplasma gondii, Rubella virus, Cytomegalovirus or Herpes simplex virus, often infects the pregnant women to induce the the fetus or newborn infection by transplacental infection or exposure to contaminated genital tract secretions at delivery. Increasing evidence have been confirmed that the infection of TORCH may cause the miscarriage, premature birth, malformed fetus, stillbirth, intrauterine growth retardation, neonatal multiple organ dysfunction and other adverse pregnancy outcomes. For most TORCH-infections cases may lacking the effective treatments during pregnancy, and it is important to achieve the effacing monitoring of TORCH infections before and during pregnancy. The laboratory testing of TORCH has the great significance. However, the consensus opinions still need to improve the the standardization of TORCH testing process and the correct interpretation. Based on the characteristics of the TORCH detection method, this article gives a consensus opinion on the standardized detection and clinical application of TORCH from the laboratory perspective according to the characteristics and types of infection of different pathogens.

Objective: To explore the genetic basis of a child with idiopathic mental retardation. Methods: Clinical data and peripheral blood sample of the child were collected. Genomic DNA was extracted and subjected to copy number analysis using single nucleotide polymrophism array comparative genome hybridization (SNP-aCGH) and targeted capture and next generation sequencing (NGS). Results: No microdeletion/microduplication were detected by SNP-aCGH. NGS has detected homozygous c. 722delA(p.Asp241fs) variant of the LISN1 gene, which is known to underlie autosomal recessive mental retardation - 27 (MRT 27). Both parents are carriers of the variant, conforming to the autosomal recessive inheritance. Conclusion A novel pathogenic variant of the LINS1 gene has been identified, which probably underlies the MRT 27 in the patient.

OBJECTIVE: To provide genetic testing and prenatal diagnosis for a woman with Sheldon-Hall syndrome. METHODS: The woman was subjected to targeted capture and next-generation sequencing for variant of genes associated with skeletal disorders. And the result was verified in her parents and fetus. RESULTS: The woman was found to harbor a c.188G>A variant of the TNNT3 gene, which was also found in her affected mother and the fetus. Her grandmother and grandmother's brother had similar manifestations, which was in line with an autosomal dominant inheritance. The same variant was not found in her father. CONCLUSION The c.188G>A variant of the TNNT3 gene probably underlay the distal joint contracture in this pedigree, based on which prenatal diagnosis was attained.