Objective:To analyze the carrier rates and profiles of pathogenic and likely pathogenic variants for hearing loss-related genes MYO7A, PCDH15, and CDH23 among neonates in Nanjing city through targeted next-generation sequencing (NGS). Methods:Heel-prick blood samples were collected from 30 043 newborns delivered at Nanjing Women and Children′s Health Care Hospital between March 2022 and April 2024. Dried blood spots were prepared, and genomic DNA was extracted. Targeted NGS was applied to detect variants across the full coding regions of the MYO7A, PCDH15, and CDH23 genes. The carrier rates and profiles of pathogenic and likely pathogenic variants of the three genes were analyzed. This study was approved by the Medical Ethics Committee of Nanjing Maternal and Child Health Care Hospital (Ethics No.: 2021KY-071). Results:The carrier rates of pathogenic and likely pathogenic variants (with ≥ 1 variant site) for the MYO7A, PCDH15, and CDH23 genes were 0.340%, 0.226%, and 0.156%, respectively. A total of 65, 49, and 30 variant types were detected in the MYO7A, PCDH15, and CDH23 genes, respectively. For MYO7A, single base variants were predominant, with the most common variant being c. 5581C>T, followed by c. 1343+ 1G>A, c. 2837T>G, and c. 5660C>T, with allelic frequencies of 0.013% (8/60 086), 0.007% (4/60 086), 0.007% (4/60 086), and 0.007% (4/60 086), respectively. PCDH15 variants were mainly deletions, with the most common variant site being c. 4699_4715dupAGAGAAAAGATTCAGAG, followed by c. 3441delA, c. 440T>G, and c. 4733_4736delTCAG, with allelic frequencies of 0.015% (9/60 086), 0.005% (3/60 086), 0.005% (3/60 086), and 0.005% (3/60 086), respectively. For CDH23, single base variants were predominant, with c. 6604G>A being the most common, followed by c. 6085C>T, c. 6050+ 9G>A, and c. 6253+ 1G>A, with allelic frequencies of 0.013% (8/60 086), 0.012% (7/60 086), 0.005% (3/60 086), and 0.005% (3/60 086). Conclusion:This study analyzed the carrier rates and profiles of pathogenic and likely pathogenic variants of the MYO7A, PCDH15, and CDH23 genes, which can provide more evidence for the prevention and management of deafness in the region.

Objective To investigate the clinical significance of the combined screening of thyroid stimulating hormone(TSH)and seven candidate pathogenic genes of congenital hypothyroidism(CH)for CH.Methods 16 645 newborns delivered in Nanjing Women and Children's Healthcare Hospital from July 2022 to July 2023 were performed the screening of TSH.Their DNA was extracted from dried blood spots and the chip capture second-generation sequencing technology was used to detect the candidate pathogenic genes,in-cluding dual oxidase 2(DUOX2),dual oxidase maturation factor 2(DUOXA2),prophet of pit-1(PROP1),thyroid-stimulating hor-mone receptor(TSHR),thyroid peroxidase(TPO),thyroglobulin(TG),and paired box 8(PAX8).The sensitivity,specificity,pos-itive predictive value(PPV),and negative predictive value(NPV)of the screening of TSH,candidate genes,and their combination for CH were analyzed.Results A total of 13 CH patients were screened out based on sensitive thyroid stimulating hormone(sTSH)and free thyroxine(FT4),including 3 patients with hyperthyrotropinemia.Among them,11 were screened out by TSH alone,4 were screened out by candidate genes alone,and 2 were screened out by the combination of TSH and candidate genes.The sensitivity,speci-ficity,PPV,and NPV of TSH for screening CH were 84.62％,99.23％,7.91％,and 99.97％,respectively.The sensitivity,specifici-ty,PPV,and NPV of candidate genes for screening CH were 30.77％,99.87％,15.38％,and 99.87％,respectively.The sensitivity,specificity,PPV,and NPV of the combination of TSH and candidate genes for screening CH were 100％,99.09％,7.88％,and 100％,respectively.The primary mutant gene in the samples with positive candidate genes was DUOX2(85.71％),mainly point muta-tions,among which the c.1588A>T variant was the most common(16.67％).PAX8(14.29％)was the second most common variation,and all of the variation point were c.280G>A.No positive samples for the pathogenic variants of DUOXA2,TSHR,PROP1,TPO,and TG were detected.Conclusion The combined screening of TSH and candidate genes helps to improve the screening efficacy of CH.The genetic etiology of CH in Nanjing area may be mainly the variation of DUOX2 and PAX8 genes.

Objective:To assess the prevalence of pathogenic variants in the acid alpha-glucosidase ( GAA) gene among newborns in Nanjing and provide a reference for early screening, diagnosis, and treatment of Pompe disease. Methods:This retrospective study conducted on 30 043 live births at Women's Hospital of Nanjing Medical University (Nanjing Women and Children's Healthcare Hospital) from March 2022 to October 2024. Heel blood samples were collected within 48 h after birth to make dried blood spots. Chip-capture-based next-generation sequencing was used to detect pathogenic/likely pathogenic (P/LP) GAA variants. Suspected cases underwent Sanger sequencing validation and GAA enzyme activity assay to summarize the carrier status of pathogenic variants in the GAA gene among newborns. Descriptive statistical analysis was used. Results:Among the 30 043 newborns, 232 carriers (one P/LP variant) and four presumptive cases (two P/LP variants) were identified. The GAA activity of suspected cases 1 and 2 was normal, and the two variants were in cis, leading to a clinical diagnosis of carriers. Presumptive case 3 had a GAA activity of 0.17 μmol/(L·h), below the normal range [2.63-21.69 μmol/(L·h)]; the two variants were in trans, without clinical manifestations of Pompe disease follow-up to 2 years and 1 month, resulting in a clinical diagnosis of a potential patient. Presumptive case 4 had a GAA activity of 0.36 μmol/(L·h), below the normal range; the two variants were in cis, and two pseudodeficiency variants [c.1726G>A(p.G576S) and c.2065G>A(p.E689K)] were also found, leading to a final clinical diagnosis of a carrier. Therefore, a total of 235 carriers of P/LP GAA variants were identified, with a carrying rate of 1/128 (235/30 043), and one potential patient was identified with an incidence rate of 1/30 043. The top five common GAA variants were c.2132_2133delinsGG, c.503G>A, c.-32-13T>G, c.2662G>T, and c.2238G>C, with allele frequencies of 0.078% (47/60 086), 0.038% (23/60 086), 0.020% (12/60 086), 0.018% (11/60 086), and 0.017% (10/60 086), respectively. Protein structure prediction results showed that c.2132_2133delinsGG resulted in a shortened two β-sheet in GH31(β/α) 8 barrel catalytic domain and altered signal peptide and prepeptide conformation. c.503G>A would extend one β-sheet and add an additional β-sheet in the N-terminal domain. Conclusion:Newborn genetic screening combined with GAA activity measurement can exclude the interference of pseudodeficiency alleles, improve screening efficiency and accuracy, and provide a reference for the clinical diagnosis and genetic counseling of Pompe disease.

Objective:Objective To analyze the carrier rates and mutational spectrum of pathogenic variants in deafness-associated genes among newborns in Nanjing.Methods:In this cross-sectional study, heel blood samples were collected from 30 043 neonates born at Nanjing Maternity and Child Health Care Hospital between March 2022 and April 2024. DNA was extracted from dried blood spots and subjected to targeted next-generation sequencing of the full coding regions of deafness-associated genes GJB2, SLC26A4, USH2A, MT-RNR1, and MYO15A. Descriptive statistics were used to analyze carrier rates and variant characteristics, with pathogenicity classified according to American College of Medical Genetics and Genomics guidelines. Results:(1) Carrier rates: The overall carrier rate for deafness-associated gene variants was 19.196% (5 767/30 043). GJB2 showed the highest carrier rate at 13.174% (3 958/30 043), followed by SLC26A4 (2.912%, 875/30 043), USH2A (1.524%, 458/30 043), MT- RNR1 (0.959%, 288/30 043), and MYO15A (0.626%, 188/30 043). MT-RNR1 follows mitochondrial inheritance, while others are autosomal recessive. (2) Variant analysis revealed: 25 GJB2 variants with c.109G>A being most frequent (allele frequency 4.925%, 2 959/60 086), followed by c.235delC (1.127%, 677/60 086) and c.299_300delAT (0.261%, 157/60 086); 85 SLC26A4 variants dominated by c.919-2A>G (0.621%, 373/60 086), c.2009T>C (0.165%, 99/60 086), and c.2168A>G (0.100%, 60/60 086); 118 USH2A variants with c.2802T>G (0.218%, 131/60 086) and c.8559-2A>G (0.165%, 99/60 086) most prevalent; three MT-RNR1 variants including m.1095T>C (230 cases), m.1555A>G (52 cases), and m.1494C>T (six cases); and 81 MYO15A variants with c.10250_10252delCCT (0.043%, 26/60 086) being most common. Conclusion:The predominant pathogenic variants in deafness-associated genes among Nanjing neonates are GJB2 c.109G>A and SLC26A4 c.919-2A>G, with MT- RNR1 m.1095T>C representing a significant mitochondrial variant.

OBJECTIVE: To analyze the carrier rates and profiles of pathogenic and likely pathogenic variants for hearing loss-related genes MYO7A, PCDH15, and CDH23 among neonates in Nanjing city through targeted next-generation sequencing (NGS). METHODS: Heel-prick blood samples were collected from 30 043 newborns delivered at Nanjing Women and Children's Health Care Hospital between March 2022 and April 2024. Dried blood spots were prepared, and genomic DNA was extracted. Targeted NGS was applied to detect variants across the full coding regions of the MYO7A, PCDH15, and CDH23 genes. The carrier rates and profiles of pathogenic and likely pathogenic variants of the three genes were analyzed. This study was approved by the Medical Ethics Committee of Nanjing Maternal and Child Health Care Hospital (Ethics No.: 2021KY-071). RESULTS: The carrier rates of pathogenic and likely pathogenic variants (with ≥ 1 variant site) for the MYO7A, PCDH15, and CDH23 genes were 0.340%, 0.226%, and 0.156%, respectively. A total of 65, 49, and 30 variant types were detected in the MYO7A, PCDH15, and CDH23 genes, respectively. For MYO7A, single base variants were predominant, with the most common variant being c.5581C>T, followed by c.1343+1G>A, c.2837T>G, and c.5660C>T, with allelic frequencies of 0.013% (8/60 086), 0.007% (4/60 086), 0.007% (4/60 086), and 0.007% (4/60 086), respectively. PCDH15 variants were mainly deletions, with the most common variant site being c.4699_4715dupAGAGAAAAGATTCAGAG, followed by c.3441delA, c.440T>G, and c.4733_4736delTCAG, with allelic frequencies of 0.015% (9/60 086), 0.005% (3/60 086), 0.005% (3/60 086), and 0.005% (3/60 086), respectively. For CDH23, single base variants were predominant, with c.6604G>A being the most common, followed by c.6085C>T, c.6050+9G>A, and c.6253+1G>A, with allelic frequencies of 0.013% (8/60 086), 0.012% (7/60 086), 0.005% (3/60 086), and 0.005% (3/60 086). CONCLUSION This study analyzed the carrier rates and profiles of pathogenic and likely pathogenic variants of the MYO7A, PCDH15, and CDH23 genes, which can provide more evidence for the prevention and management of deafness in the region.
Humans ; Cadherins/genetics* ; High-Throughput Nucleotide Sequencing/methods* ; Infant, Newborn ; Female ; Myosin VIIa/genetics* ; Cadherin Related Proteins ; Male ; Hearing Loss/genetics* ; Myosins/genetics* ; Heterozygote

Objective To analyze the results of newborn screening for galactocerebrosidase(GALC)gene and enzyme activity and pro-vide a basis for the clinical diagnosis and genetic counseling of Krabbe disease.Methods The dried blood samples on filter paper from 12 744 newborns born at Nanjing Women and Children's Healthcare Hospital from March 18,2022 to December 31,2022 were collect-ed.The pathogenic variant sites of GALC gene were detected using the chip capture next-generation sequencing technology and Sanger sequencing was used for family validation.The tandem mass spectrometry was used to determine the enzyme activity of GALC in dried blood spots.The comparison of GALC enzyme activity between the carriers with GALC variants and negative group was conducted using the independent sample t-test.Results Among the 12 744 newborns,315 were identified as the carriers with GALC variants,with a carrier rate of 1/40.The most common variant was c.1901T＞C(269 cases,1/47),followed by c.1592G＞A(12 cases,1/1 062).Four newborns(P1-P4)were found to have two pathogenic variant sites and 2 cases were homozygous variants of c.1901T＞C.Family validation showed that the two variant sites in the four newborns were inherited from their parents,leading to a diagnosis of Krabbe dis-ease.Meanwhile,the family validation of the potential P2 patient's sister revealed that they had the same genotype,and the diagnosis of Krabbe disease was made.A preliminary threshold of 0.42 μmol/(L·h)for the enzyme activity of GALC detected by the tandem mass spectrometry was established based on 200 newborn samples.The GALC enzyme activities of 4 children with Krabbe disease were 0.74,0.21,0.17,and 0.29 μmol/(L·h),respectively.The GALC enzyme activity of the P2 patient's sister was 0.28 μmol/(L·h).Except for the P1 patient,the GALC enzyme activities of the P2,P3,and P4 patients and the P2 patient's sister were reduced,indica-ting a positive result.Conclusion The carrier rate of pathogenic variants in the GALC gene is relatively high,with the hotspot mutation being c.1901T＞C.The estimated prevalence of Krabbe disease is 1/3 186.The screening strategy using genetic testing as the primary screening and enzyme activity testing as the second screening can effectively improve the diagnostic efficiency of Krabbe disease,provi-ding a reference for the clinical diagnosis and genetic counseling of Krabbe disease.

Hepatolenticular degeneration is a treatable genetic metabolic disorder with serious clinical implications. Early treatment leads to a better prognosis. Large-scale population screening in the neonatal period can effectively identify presymptomatic patients, achieving the goal of early detection, diagnosis, and treatment. This article introduces clinical protocols applicable for screening for newborns with hepatolenticular degeneration, along with emerging detection technologies that promote progress in newborn screening. The former mainly includes ceruloplasmin screening and ATP7B gene screening, while the latter mainly consists of metabolomics techniques, ATP7B peptide detection, proteomics techniques, and whole-genome sequencing. The article also provides a perspective on the future of newborn screening for this disease.

Objective:To analyze the carrier rates and profiles of pathogenic and likely pathogenic variants for hearing loss-related genes MYO7A, PCDH15, and CDH23 among neonates in Nanjing city through targeted next-generation sequencing (NGS). Methods:Heel-prick blood samples were collected from 30 043 newborns delivered at Nanjing Women and Children′s Health Care Hospital between March 2022 and April 2024. Dried blood spots were prepared, and genomic DNA was extracted. Targeted NGS was applied to detect variants across the full coding regions of the MYO7A, PCDH15, and CDH23 genes. The carrier rates and profiles of pathogenic and likely pathogenic variants of the three genes were analyzed. This study was approved by the Medical Ethics Committee of Nanjing Maternal and Child Health Care Hospital (Ethics No.: 2021KY-071). Results:The carrier rates of pathogenic and likely pathogenic variants (with ≥ 1 variant site) for the MYO7A, PCDH15, and CDH23 genes were 0.340%, 0.226%, and 0.156%, respectively. A total of 65, 49, and 30 variant types were detected in the MYO7A, PCDH15, and CDH23 genes, respectively. For MYO7A, single base variants were predominant, with the most common variant being c. 5581C>T, followed by c. 1343+ 1G>A, c. 2837T>G, and c. 5660C>T, with allelic frequencies of 0.013% (8/60 086), 0.007% (4/60 086), 0.007% (4/60 086), and 0.007% (4/60 086), respectively. PCDH15 variants were mainly deletions, with the most common variant site being c. 4699_4715dupAGAGAAAAGATTCAGAG, followed by c. 3441delA, c. 440T>G, and c. 4733_4736delTCAG, with allelic frequencies of 0.015% (9/60 086), 0.005% (3/60 086), 0.005% (3/60 086), and 0.005% (3/60 086), respectively. For CDH23, single base variants were predominant, with c. 6604G>A being the most common, followed by c. 6085C>T, c. 6050+ 9G>A, and c. 6253+ 1G>A, with allelic frequencies of 0.013% (8/60 086), 0.012% (7/60 086), 0.005% (3/60 086), and 0.005% (3/60 086). Conclusion:This study analyzed the carrier rates and profiles of pathogenic and likely pathogenic variants of the MYO7A, PCDH15, and CDH23 genes, which can provide more evidence for the prevention and management of deafness in the region.

Hepatolenticular degeneration is a treatable genetic metabolic disorder with serious clinical implications. Early treatment leads to a better prognosis. Large-scale population screening in the neonatal period can effectively identify presymptomatic patients, achieving the goal of early detection, diagnosis, and treatment. This article introduces clinical protocols applicable for screening for newborns with hepatolenticular degeneration, along with emerging detection technologies that promote progress in newborn screening. The former mainly includes ceruloplasmin screening and ATP7B gene screening, while the latter mainly consists of metabolomics techniques, ATP7B peptide detection, proteomics techniques, and whole-genome sequencing. The article also provides a perspective on the future of newborn screening for this disease.

Objective To analyze the results of newborn screening for galactocerebrosidase(GALC)gene and enzyme activity and pro-vide a basis for the clinical diagnosis and genetic counseling of Krabbe disease.Methods The dried blood samples on filter paper from 12 744 newborns born at Nanjing Women and Children's Healthcare Hospital from March 18,2022 to December 31,2022 were collect-ed.The pathogenic variant sites of GALC gene were detected using the chip capture next-generation sequencing technology and Sanger sequencing was used for family validation.The tandem mass spectrometry was used to determine the enzyme activity of GALC in dried blood spots.The comparison of GALC enzyme activity between the carriers with GALC variants and negative group was conducted using the independent sample t-test.Results Among the 12 744 newborns,315 were identified as the carriers with GALC variants,with a carrier rate of 1/40.The most common variant was c.1901T＞C(269 cases,1/47),followed by c.1592G＞A(12 cases,1/1 062).Four newborns(P1-P4)were found to have two pathogenic variant sites and 2 cases were homozygous variants of c.1901T＞C.Family validation showed that the two variant sites in the four newborns were inherited from their parents,leading to a diagnosis of Krabbe dis-ease.Meanwhile,the family validation of the potential P2 patient's sister revealed that they had the same genotype,and the diagnosis of Krabbe disease was made.A preliminary threshold of 0.42 μmol/(L·h)for the enzyme activity of GALC detected by the tandem mass spectrometry was established based on 200 newborn samples.The GALC enzyme activities of 4 children with Krabbe disease were 0.74,0.21,0.17,and 0.29 μmol/(L·h),respectively.The GALC enzyme activity of the P2 patient's sister was 0.28 μmol/(L·h).Except for the P1 patient,the GALC enzyme activities of the P2,P3,and P4 patients and the P2 patient's sister were reduced,indica-ting a positive result.Conclusion The carrier rate of pathogenic variants in the GALC gene is relatively high,with the hotspot mutation being c.1901T＞C.The estimated prevalence of Krabbe disease is 1/3 186.The screening strategy using genetic testing as the primary screening and enzyme activity testing as the second screening can effectively improve the diagnostic efficiency of Krabbe disease,provi-ding a reference for the clinical diagnosis and genetic counseling of Krabbe disease.