Next generation sequencing (NGS) technology is playing an increasingly important role in the diagnosis of genetic diseases. Whole exome sequencing (WES), which targets the coding regions of the genome, has been widely used in the diagnosis of genetic diseases for its low cost and high efficiency. However, compared to conventional methods, the Next Generation Sequencing (NGS) process is intricate, and there is variability in the expertise of data analysts and variant interpreters, which may lead to inconsistencies in the outcomes. To ensure the quality of testing and enhance the diagnostic rate of diseases, this consensus has provided recommendations regarding the laboratory setup, operational procedures, data analysis, result interpretation, and quality control for WES, with an aim to standardize its application in the detection of genetic disorders.

Objective·To investigate the genetic etiology of a rare and complex case clinically suspected to be methylmalonic acidemia(MMA),but with negative whole exome sequencing(WES)results,using a multi-omics sequencing approach.Methods·DNA and RNA samples were extracted from the peripheral blood of the proband and both parents.Targeted MMA-related gene Panel sequencing and WES were first performed.Subsequently,RNA sequencing(RNA-seq)and whole genome sequencing(WGS)were conducted to comprehensively analyze the child's genetic variants,their origins and potential inheritance patterns.Results·No pathogenic variants associated with the patient's phenotype were identified through the MMA Panel or standard WES analysis.Extended analysis of WES suggested the possibility of uniparental disomy(UPD)of chromosome 4.WGS revealed a homozygous splice-site variant(c.-66+2T>C)in the non-coding region of the metabolism of cobalamin associated A(MMAA)gene.The variant was located in the 5'untranslated region(5'UTR),specifically at the second base downstream of the splice donor site of exon 1(reference sequence:NM_172250).In genomic coordinates(hg19),the variant was located at base 146540561 on chromosome 4(chr4:146540561).Sanger sequencing confirmed that the mother was heterozygous for this variant,while the father did not carry it.RNA-seq showed no detectable expression of the MMAA gene on chromosome 4 in the patient.This was further confirmed by reverse transcription real time quantitative PCR,indicating nearly absent mRNA expression,suggesting that the non-coding splice-site variant affected transcriptional expression.Conclusion·A homozygous splice-site variant(c.-66+2T>C)in the non-coding region of the MMAA gene—outside the coverage of WES—is likely the pathogenic cause in this case,presumably resulting from maternal UPD of chromosome 4.

Accurate timing of myelination is crucial for the proper functioning of the central nervous system. Here, we identified a de novo heterozygous mutation in TMEM63A (c.1894G>A; p. Ala632Thr) in a 7-year-old boy exhibiting hypomyelination. A Ca²⁺ influx assay suggested that this is a loss-of-function mutation. To explore how TMEM63A deficiency causes hypomyelination, we generated Tmem63a knockout mice. Genetic deletion of TMEM63A resulted in hypomyelination at postnatal day 14 (P14) arising from impaired differentiation of oligodendrocyte precursor cells (OPCs). Notably, the myelin dysplasia was transient, returning to normal levels by P28. Primary cultures of Tmem63a^-/- OPCs presented delayed differentiation. Lentivirus-based expression of TMEM63A but not TMEM63A_A632T rescued the differentiation of Tmem63a^-/- OPCs in vitro and myelination in Tmem63a^-/- mice. These data thus support the conclusion that the mutation in TMEM63A is the pathogenesis of the hypomyelination in the patient. Our study further demonstrated that TMEM63A-mediated Ca²⁺ influx plays critical roles in the early development of myelin and oligodendrocyte differentiation.
Animals ; Cell Differentiation/physiology* ; Oligodendroglia/metabolism* ; Mice, Knockout ; Mice ; Male ; Myelin Sheath/metabolism* ; Humans ; Child ; Cells, Cultured ; Oligodendrocyte Precursor Cells/metabolism*

Objective To investigate the effect of inhibiting stearoyl-CoA desaturase 1(SCD1)activity on the biological behavior of cervical cancer cells and elucidate the molecular mechanisms related to fatty acid metabolism.Methods Cancer tissues were collected from 48 patients with cervical cancer,whereas normal cervical tissues were obtained from 48 patients with uterine fibroids.Immunohisto-chemical SP staining and real-time quantitative PCR were performed to assess differences in SCD1 expression.The MTS assay was used to determine cell viability,and EdU staining was conducted to evaluate cell proliferation.Cell migration and invasion abilities were analyzed using in vitro scratch assay and Transwell chamber assay.Immunofluorescence staining was performed to detect E-cadherin and vimentin expression.Real-time quantitative PCR was used to measure the mRNA expression levels of SREBP1,ACLY,ACC,and FAS.Nile red fluorescence staining was applied to observe intracellular lipid droplet content.Results The positive expression rate of SCD1 and the relative expression level of SCD1 mRNA were significantly higher in cervical cancer tissues than in normal cervical tissues(P＜0.05).Treatment of HeLa cells with varying concentrations of MF-438 led to significant reductions in cell viability,EdU-positive cell rate,scratch closure rate,and the number of migrating and invading cells.Additionally,the fluorescence intensity of E-cadherin increased,whereas that of vimentin decreased.The relative expression levels of SREBP1,A CL Y,ACC,and FAS mRNA were downregulated,and intracellular lipid droplet content decreased in a concentration-dependent manner(P＜0.05).Conclusion Inhibition of SCD1 activity significantly reduced lipid metabolism in HeLa cells and suppressed malignant biological behaviors,including proliferation,migration,invasion,and epithelial-mesenchymal transition.

Objective·To investigate the genetic etiology of a rare and complex case clinically suspected to be methylmalonic acidemia(MMA),but with negative whole exome sequencing(WES)results,using a multi-omics sequencing approach.Methods·DNA and RNA samples were extracted from the peripheral blood of the proband and both parents.Targeted MMA-related gene Panel sequencing and WES were first performed.Subsequently,RNA sequencing(RNA-seq)and whole genome sequencing(WGS)were conducted to comprehensively analyze the child's genetic variants,their origins and potential inheritance patterns.Results·No pathogenic variants associated with the patient's phenotype were identified through the MMA Panel or standard WES analysis.Extended analysis of WES suggested the possibility of uniparental disomy(UPD)of chromosome 4.WGS revealed a homozygous splice-site variant(c.-66+2T>C)in the non-coding region of the metabolism of cobalamin associated A(MMAA)gene.The variant was located in the 5'untranslated region(5'UTR),specifically at the second base downstream of the splice donor site of exon 1(reference sequence:NM_172250).In genomic coordinates(hg19),the variant was located at base 146540561 on chromosome 4(chr4:146540561).Sanger sequencing confirmed that the mother was heterozygous for this variant,while the father did not carry it.RNA-seq showed no detectable expression of the MMAA gene on chromosome 4 in the patient.This was further confirmed by reverse transcription real time quantitative PCR,indicating nearly absent mRNA expression,suggesting that the non-coding splice-site variant affected transcriptional expression.Conclusion·A homozygous splice-site variant(c.-66+2T>C)in the non-coding region of the MMAA gene—outside the coverage of WES—is likely the pathogenic cause in this case,presumably resulting from maternal UPD of chromosome 4.

Objective To investigate the effect of inhibiting stearoyl-CoA desaturase 1(SCD1)activity on the biological behavior of cervical cancer cells and elucidate the molecular mechanisms related to fatty acid metabolism.Methods Cancer tissues were collected from 48 patients with cervical cancer,whereas normal cervical tissues were obtained from 48 patients with uterine fibroids.Immunohisto-chemical SP staining and real-time quantitative PCR were performed to assess differences in SCD1 expression.The MTS assay was used to determine cell viability,and EdU staining was conducted to evaluate cell proliferation.Cell migration and invasion abilities were analyzed using in vitro scratch assay and Transwell chamber assay.Immunofluorescence staining was performed to detect E-cadherin and vimentin expression.Real-time quantitative PCR was used to measure the mRNA expression levels of SREBP1,ACLY,ACC,and FAS.Nile red fluorescence staining was applied to observe intracellular lipid droplet content.Results The positive expression rate of SCD1 and the relative expression level of SCD1 mRNA were significantly higher in cervical cancer tissues than in normal cervical tissues(P＜0.05).Treatment of HeLa cells with varying concentrations of MF-438 led to significant reductions in cell viability,EdU-positive cell rate,scratch closure rate,and the number of migrating and invading cells.Additionally,the fluorescence intensity of E-cadherin increased,whereas that of vimentin decreased.The relative expression levels of SREBP1,A CL Y,ACC,and FAS mRNA were downregulated,and intracellular lipid droplet content decreased in a concentration-dependent manner(P＜0.05).Conclusion Inhibition of SCD1 activity significantly reduced lipid metabolism in HeLa cells and suppressed malignant biological behaviors,including proliferation,migration,invasion,and epithelial-mesenchymal transition.

Next generation sequencing (NGS) technology is playing an increasingly important role in the diagnosis of genetic diseases. Whole exome sequencing (WES), which targets the coding regions of the genome, has been widely used in the diagnosis of genetic diseases for its low cost and high efficiency. However, compared to conventional methods, the Next Generation Sequencing (NGS) process is intricate, and there is variability in the expertise of data analysts and variant interpreters, which may lead to inconsistencies in the outcomes. To ensure the quality of testing and enhance the diagnostic rate of diseases, this consensus has provided recommendations regarding the laboratory setup, operational procedures, data analysis, result interpretation, and quality control for WES, with an aim to standardize its application in the detection of genetic disorders.

To explore the value of CNVPLUS ?-array in the diagnosis of the DMD gene. A retrospective study was performed on 96 children who were clinically diagnosed with Duchenne or Becker muscular dystrophies(DMD/BMD) at the Department of Pediatric Endocrinology and Genetics of Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine from January 2014 to March 2023. DNA was extracted from these children′s peripheral blood and divided into two parts. Variations of the DMD gene were detected by using CNVPLUS ?-array and sequential testing of MLPA—NGS—Sanger. In the sequential method, single exon deletions detected by MLPA were first verified by polymerase chain reaction (PCR) and then were tested by Sanger′s sequencing if PCR results were normal. The results showed that, among 96 samples, 91 cases with the pathogenic variation of the DMD gene were detected by the CNVPLUS ?-array, including 76 cases with large deletion/duplication (copy number variation, CNV) and 15 cases with small variation (single nucleotide variant or small insertion/deletion, SNV/Indel). All samples were tested and diagnosed within 5 days. In contrast, 76 cases with pathogenic CNV and 20 cases with pathogenic SNV/Indel were detected in the DMD gene by sequential method. However, all of the experiments and diagnoses were completed within 48 days. Moreover, 5 cases with SNV/Indel in the DMD gene were correctly clustered after the operation mode was optimized. In summary, as a new micro-array integrating CNV and SNV probes, CNVPLUS ?-array can detect CNV and SNV/Indel in the DMD gene simultaneously while the application of CNVPLUS ?-array could save a lot of time and manpower. CNVPLUS ?-array had an excellent diagnostic performance for CNV of the DMD gene. As for SNV/Indel, the diagnostic performance was slightly poor and the operation mode should be optimized. If necessary, other testing technologies should be supplemented to reduce the risk of missed diagnosis.

Objective:To assess the application value of CNVPLUS ?-array for the genetic analysis of spinal muscular atrophy (SMA). Methods:From June 2021 to December 2022, CNVPLUS ?-array technique was employed to test the SMN1 and SMN2 genes among peripheral blood samples from 17 suspected SMA patients, 18 core families with suspected SMA, and 25 healthy individuals. The results were compared with those of multiple ligation-dependent probe amplification (MLPA) assay. Samples with inconsistent results were subjected to nested PCR or comprehensive analysis of SMA. This study was approved by the Shanghai Institute for Pediatric Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (Ethics No. XHEC-D-2024-038). Results:CNVPLUS ?-array has identified 35 SMA patients, 36 carriers, and 25 healthy individuals. In comparison, MLPA has identified 34 SMA patients, 36 carriers, and 26 healthy individuals. The two methods demonstrated a high consistency ( Kappa = 0.968, P<0.001). Additionally, CNVPLUS ?-array has identified one patient with compound heterozygous variants of SMN1 and one carrier with a [2+ 0] genotype. Conclusion:CNVPLUS ?-array not only can accurately determine the copy numbers of SMN1 and SMN2 genes, but also identify point mutations in SMN1 and [2+ 0] carriers, which has offered a new method for the genetic testing of SMA.

To explore the value of CNVPLUS ?-array in the diagnosis of the DMD gene. A retrospective study was performed on 96 children who were clinically diagnosed with Duchenne or Becker muscular dystrophies(DMD/BMD) at the Department of Pediatric Endocrinology and Genetics of Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine from January 2014 to March 2023. DNA was extracted from these children′s peripheral blood and divided into two parts. Variations of the DMD gene were detected by using CNVPLUS ?-array and sequential testing of MLPA—NGS—Sanger. In the sequential method, single exon deletions detected by MLPA were first verified by polymerase chain reaction (PCR) and then were tested by Sanger′s sequencing if PCR results were normal. The results showed that, among 96 samples, 91 cases with the pathogenic variation of the DMD gene were detected by the CNVPLUS ?-array, including 76 cases with large deletion/duplication (copy number variation, CNV) and 15 cases with small variation (single nucleotide variant or small insertion/deletion, SNV/Indel). All samples were tested and diagnosed within 5 days. In contrast, 76 cases with pathogenic CNV and 20 cases with pathogenic SNV/Indel were detected in the DMD gene by sequential method. However, all of the experiments and diagnoses were completed within 48 days. Moreover, 5 cases with SNV/Indel in the DMD gene were correctly clustered after the operation mode was optimized. In summary, as a new micro-array integrating CNV and SNV probes, CNVPLUS ?-array can detect CNV and SNV/Indel in the DMD gene simultaneously while the application of CNVPLUS ?-array could save a lot of time and manpower. CNVPLUS ?-array had an excellent diagnostic performance for CNV of the DMD gene. As for SNV/Indel, the diagnostic performance was slightly poor and the operation mode should be optimized. If necessary, other testing technologies should be supplemented to reduce the risk of missed diagnosis.