Analysis of beta-globin gene variants in Liuzhou area of Guangxi / 中华医学遗传学杂志

OBJECTIVE@#To determine the composition and distribution of beta-thalassemia-associated genotypes in Liuzhou area of Guangxi, China.@*METHODS@#From January to December 2017, 13 847 individuals who came for premarital examination, maternity examination or health check were recruited with informed consent. The subjects were analyzed by reverse dot blotting (RDB) for 17 common beta-thalassemia-associated variants among the Chinese population. Individuals with inconsistent results by blood test, electrophoresis, and RDB were subjected to Sanger sequencing to detect rare variants of the beta globin gene.@*RESULTS@#In total 2098 individuals were found to harbor beta-thalassemia-associated variants, which included 2075 heterozygotes (98.90%), 12 compound heterozygotes (0.57%) and 11 homozygotes (0.52%). CD41-42 (48.43%) and CD17 (31.45%) were the most common variants. Three hundred and thirty eight-individuals were found to also carry heterozygous variants of the alpha globin gene, with the most common types being --SEA/aa, -a3.7/aa, aCSa/aa, -a4.2/aa. Through Sanger sequencing, rare genotypes such as beta-32/betaN, betaCD41-42/betaIVS-II-5 and betaCD30/betaN were detected.@*CONCLUSION@#Liuzhou area has a high incidence of beta-thalassemia, but with a complex variant spectrum and clinical phenotypes different from other regions. Genetic counseling and prenatal diagnosis for the carrier population is crucial for the reduction of the related birth defects. Our result may provide valuable information for the prevention and control of beta-thalassemia in this area.

Construction of human YPEL5 gene eukaryotic expression vector and its expression in esophageal carcinoma cells / 国际检验医学杂志

Objective To construct human yippee-like 5(YPEL5) gene eukaryotic expression recombinant plasmid and to express in esophageal carcinoma EC9706 cells .Methods The cDNA from human normal tissue was taken as a template and amplified to YPEL5 gene coding sequence with 366 bp in length .Then this se-quence was inserted into the multiple cloning site areas of eukaryotic expression vector pCDH-CD513B for ob-taining the eukaryotic expression vector pCDH-CD513B-Flag-YPEL5 .After the bacterial colony PCR identifi-cation ,it was sent to the corporation for testing the sequence .The successfully constructed recombinant plas-mid was transfected into human esophageal carcinoma EC9706 cells .The expression of PEL5 gene in EC9706 cells was detected by QRT-PCR and Western Blot .Results The YPEL5 gene segment with 366 bp in length was successfully amplified .pCDH-CD513B-Flag-YPEL5 recombinant plasmid was obtained by double enzyme digestion ,connection ,conversion and screening .The gene sequencing identification showed that the inserted gene sequence in recombinant plasmid was consistent with that in the GenBank .After 2 d of transfecting into EC9706 cells ,the QRT-PCR and Western Blot revealed that YPEL5 gene expression was significantly up-reg-ulated .Conclusion The pCDH-CD513B-Flag-YPEL5 eukaryotic expression vector is successfully constructed and is expressed in esophageal squamous cancer cell line EC9706 ,thus which lays a foundation for studying its function in the progression of esophageal cancer .

Clinical evaluation of a melting curve analysis-based PCR assay for glucose phosphate dehydrogenase gene mutation detection / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical value of multicolor melting curve analysis(MMCA) for detecting genetic mutations in G6PD deficiency.</p><p><b>METHODS</b>A total of 402 peripheral blood samples(256 males and 146 females) were collected from suspected patients or their relatives at the Prenatal Diagnosis Center of Liuzhou Maternal and Child Health Hospital between March 2012 and May 2012. The samples were screened by G6PD/6PGD quantitative ratio testing. The reliability of the assay was evaluated by multiplex probe melting curve assay(which can detect 16 G6PD mutations) and DNA sequencing through a double blind study.</p><p><b>RESULTS</b>One hundred seventy cases with G6PD/6PGD ratio < 1.0 and 232 cases with G6PD/6PGD ratio ≥ 1.0 were detected by the enzymological method. DNA sequencing has identified 182 wild type samples, 151 hemizygous mutation samples, 5 female homozygous mutation samples, 54 female heterozygous mutation samples and 10 female double heterozygous mutation samples. Multicolor melting curve analysis has detected 185 wild type samples, 148 hemizygous mutation samples, 5 female homozygous mutation samples, 55 female heterozygous mutation samples and 9 female double heterozygous mutation samples. The specificity and sensitivity of G6PD gene mutation detection by multicolor melting curve analysis were 100%(182/182) and 98.6%(217/220), respectively. The positive predictive value and negative predictive value were 99.5%(216/217) and 98.4%(182/185), respectively, and the Youden's index was 0.986. The concordance rate of the sample detection between the melting curve assay and DNA sequencing was 99.0%(398/402). Twenty-one different genotypes were detected by the multicolor melting curve analysis and 24 different genotypes were detected by DNA sequencing. Four samples containing mutations(c.196T>A or c.406C>T) were not detected by multicolor melting curve analysis, which can be attributed to different technical settings of the two methods.</p><p><b>CONCLUSION</b>Multicolor melting curve analysis for G6PD gene mutation detection is a simple, rapid, sensitive and specific method, which can be used for clinical diagnosis of G6PD deficiency.</p>

The evaluation of a melting curve analysis-based PCR assay for the clinical genetic diagnosis and prenatal diagnosis of β-thalassemia / 中华检验医学杂志

ObjectivesTo investigate the clinical value of the melting curve analysis-based PCR assay for the clinical genetic diagnosis and prenatal diagnosis of β-thalassemia.Methods A total of 451 peripheral blood samples,including 372 cases with β-thalassemia phenotypes and 79 cases without β-thalassemia phenotypes,were collected by Liuzhou Municipal Maternity and Child Healthcare Hospital between January 2011 and August 2011.Moreover,another 84 cases,including 16 fetal villi samples (10 - 13 weeks),64 amniotic fluid samples (16 -24 weeks ) and 4 umbilical cord blood samples (above 17 weeks),whose parents were β-thalassemia carriers,were also collected for this assay between June 2011 and September 2011.A double-blind test was done to compare the detection reliability of the melting curve analysis-based assay (24 β-thalassemia mutations can be detected) with PCR-RDB probe assay (17 β-thalassemia mutations can be detected ) and DNA sequencing using these samples.The wildtype,mutant and total concordance rates of the genotyping results were calculated separately among the melting curve analysis based assay,PCR-RDB probe assay and DNA sequencing.Results Among the 451 peripheral blood samples,thirteen mutations and nineteen genotypes were obtained by using melting curve analysis-based assay.447 samples had the same detection results and 4 samples had different detection results by comparing melting curve analysis-based assay with PCR-RDB probe assay,thus,the concordance rate of the sample detection result was 99.1％ (447/451),and the concordance rate of the allele detection result was 99.6％ (898/902).DNA sequencing results of the 4 samples showed that 3 samples had the same genotyping result with melting curve analysis-based assay,and 1 sample had the same genotyping result with PCR-RDB probe assay.A rare β-globin mutation which was not included by melting curve analysis-based assay was not detected.Thus,the genotypes of 450 samples were detected accurately by melting curve analysis-based assay,and the concordance rate of the sample detection between the melting curve assay and DNA sequencing assay was 99.8％ (450/451).Among 84 fetal villi,amniotic fluid,and umbilical cord blood samples,8 mutation types and 18 genotypes were obtained by using melting curve analysis-based assay.All the samples have the same detection results by comparing melting curve analysis-based assay with PCR-RDB probe assay and DNA sequencing,so the concordance rate of the genotyping results was 100％ among the melting curve analysis-based assay,PCR-RDB probe assay and DNA sequencing.Conclusions The melting curve analysis-based PCR assay can detect multiple unknown samples simultaneously,and detect multiple mutations accurately.It is very useful for the genetic diagnosis and prenatal diagnosis of β-thalassemia.