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OBJECTIVE@#To study the difference in age estimation based on quantitative analysis of DNA methylation by MassARRAY and pyrosequencing techniques.@*METHODS@#The methylation levels of 9 CpG sites from two independent whole blood sample sets (containing 65 and 62 samples) were detected using MassARRAY and pyrosequencing techniques. Z-score transformation was used to remove the batch effects of different techniques, and a linear regression model was used for age prediction.@*RESULTS@#For age prediction using the MassARRAY system, the 65 samples showed a mean absolute difference (MAD) of 2.49 years before Z-score transformation of the data and 2.44 years after the transformation, similar to the results in the 62 samples (MAD of 3.36 years before and 3.42 years after Z-score transformation). For data typed from pyrosequencing, the 65 samples showed a MAD of 4.20 years before and 2.76 years after data Z-score transformation, also similar to the results in the 62 samples (MAD of 3.92 years before and 3.63 years after data transformation).@*CONCLUSIONS@#Z-score transformation can effectively reduce the system batch effect between MassARRAY and pyrosequencing. Data from the MassARRAY system allows direct age estimation without further data processing, while the pyrosequencing data may increase the error in age estimation, which can be corrected by Z-score transformation of the data.
Subject(s)
CpG Islands/genetics , DNA Methylation , High-Throughput Nucleotide Sequencing , Linear Models , Sequence Analysis, DNAABSTRACT
OBJECTIVE: To analyze the characteristics of gene mutations of glucose-6-phosphate dehydrogenase(G6PD)deficiency in the neonates of Zhejiang Province,and discuss the genetic diversity. METHODS: A total of 2242G6PD values and blood stains on dry filter were collected from the children borned in Zhejiang Province with positive screening of G6PD deficiency between March 2015 and September 2017 in Neonatal Metabolic Screening Center of Zhejiang Province. Genomic DNA of the stains were extracted. Thirty-five gene mutation sites were detected by Mass ARRAY technology. The relationship between mutation gene sites and G6PD activity were analyzed by SPSS 22.0,taking PT,c.1388G>A,c.1024C>T,c.95 A>G,c.871G>A and c.392G>T accounted for 92.96%. There were statistically significant differences in G6PD activity of c.1376 G>T,c.1388G>A,c.1024 C>T,c.95A>G(PT has obvious regional characteristics. Using MassARRAY technology to detect specific mutation sites can be a choice as a second-level screening method for G6PD deficiency.
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Objective:To establish a method based on the iPLEX analysis of MassARRAY mass spectrometry platform to detect multiplex genetic mutations among Chinese lung cancer patients. Methods:We reviewed the related literature and data of lung cancer treatments. We also determined 99 mutation hot spots in 13 target genes, namely, EGFR, KRAS, ALK, FGFR1, FGFR2, FGFR3, PIK3CA, BRAF, PTEN, MET, ERBB2, AKT1, and STK11, which are closely related to the pathogenesis, drug resistance, and metastasis of lung cancer and are associated with relevant transduction pathways. A total of 297 primers comprising 99 paired forward and reverse amplification primers and 99 matched extension primers were designed by using Assay Design in accordance with the mutation label and format requirements of the MassARRAY platform. The detection method was established by analyzing eight cell lines and six lung cancer specimens;the proposed method was then validated through comparisons with a LungCarta kit. The sensitivity and specificity of the proposed method were evaluated by directly sequencing EGFR and KRAS genes in 100 lung cancer cases. Results:The proposed method could detect multiplex genetic mutations in the lung cancer cell lines, and this finding is consistent with that observed using previously reported methods. The proposed method could also detect such mutations in clinical lung cancer specimens;this result is also consistent with that observed by using the LungCarta kit. However, an FGFR2 mutation was detected only by using the proposed method. The measured sensitivity and specificity were 100%and 96.3%, respectively. Conclusion:The proposed MassARRAY technology-based method could detect multiplex genetic mutations among Chinese lung cancer patients. Indeed, the proposed method can be potentially applied to detect mutations in cancer cells.
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Objective To study the correlation between genetic polymorphisms of interleukin (IL)-1A/1B and susceptibility to tuberculosis (TB).Methods Genetic polymorphisms of IL-1A and IL1 B in 1032 TB patients and 1008 non-TB patients were analyzed using PCR-MassARRAY method.The correlation between genetic polymorphisms of IL-1A/1B and susceptibility to TB was statistically analyzed.Results Two tag SNPs of IL-1A and three tag SNPs of IL-1B were screened for the study.There were differences in the allele frequencies of rs2853550 and rs3783526 between TB group and non-TB group (P=0.047and P =0.034,respectively).IL-1 B SNP1 rs2853550 (P =0.025,OR =1.302,95 ％ CI =1.034-1.640,TC vs.CC) was found to be highly associated with TB,while the other SNPs showed no significant correlations with TB.Furthermore,IL-1B SNP1 rs2853550 [P=0.019,OR=1.308,95％ CI=1.045-1.638 for (TC+TT) vs.CC] in the dominant model conferred significant risk for TB,but IL-1A SNP2 rs3783526 [P=0.000,OR=0.764,95％ CI =0.591-0.988 for GG vs.(AA+GA)] in the recessive model showed protective effects against TB.The haplotype ‘TG’ in the IL-1B block showed a higher risk for TB compared with the common ‘ CA’ haplotype (P=0.032,OR=1.265,95％ CI=1.020-1.567).The diplotypes containing ‘ GA’ haplotype in IL-1A block and ‘ TG’ haplotype in IL-1B block were major risk factors for TB (for onecopy,adjusted P=0.014,OR=1.403 and 95％ CI=1.072-1.836; adjusted P=0.013,OR=1.339 and 95％ CI=1.063-1.688,respectively),but the diplotype with ‘CG’ in IL-1B block played a protective effect against TB (for two-copy,P=0.006,OR=0.664 and95％ CI=0.494-0.891).Conclusion The genetic polymorphisms of IL-1B rs2853550 might be closely associated with TB,but the GG genotype of IL1 A SNP rs3783526 might have the characteristic of anti-TB.
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Background & objectives: Cardiac malformations in the young constitute a major portion of clinically significant birth defects. Congenital heart disease (CHD) is a common congenital cardiac birth defect, affecting nearly 1 per cent of all live births. Patent ductus arteriosus (PDA) is clinically significant foetal circulation anomaly, second most common form of CHD which constitutes approximately 10 per cent of total CHDs. The study aimed to screen for TFAP2B mutations in CHD patients of Mysore. Methods: With informed consent, 100 clinically diagnosed CHD patients and 50 healthy controls in Mysore, south India, were recruited for the analysis of screening of mutations. MassARRAY analysis of 5 prominent mutations of TFAP2B was performed. Results: The analysis did not show any of the five mutations of TFAP2B screened by massARRAY in patients and controls, indicating that these mutations were not involved in the manifestation of CHD in the patients at Mysore, south India. Interpretation & Conclusions: The findings suggest the lack of involvement of known mutations of TFAP2B with syndromic or nonsyndromic CHDs in Mysore patients.