ABSTRACT
Objective To compare the advantages and disadvantages of SNPscan and Sanger sequence which are both used to detect the common deafness gene mutations in non-syndromic hearing loss (NSHL) in Gansu Province.Methods Peripheral blood samples were obtained from Dongxiang, Yugu and Baoan people with moderately severe to profound sensorineural hearing loss in Gansu province to extract genomic DNA.SNPscan was used to detect the 115 mutations in the common pathogenic GJB2 gene, SLC26A4 gene and mtDNA gene.Results We used the SNPscan to screen the mutation of GJB2 gene,mtDNA A1555G and mtDNA C1494T, SLC26A4 gene of sensorinural deafness patients from Gansu Province.The mutation rate of these three genes was 23.18% (35/151), and the mutation rate of Dongxiang, Yugu, Baoan was 21.31% (26/122), 54.54% (6/11), 16.67% (3/18), respectively.Compared with the Sanger sequence, the results were statistically insignificant(P>0.05).The detection rates in the three genes of SNPscan were 11.26% (17/151), 1.32% (2/151) and 0.66% (1/151),respectively , and the detection rates of Sanger sequence were 9.93% (15/151), 1.32% (2/151) and 0.66% (1/151) ,respectively.The results of the two methods were compared.The results were statistically insignificant (P>0.05).Time, cost and flux, SNPscan method is superior to Sanger sequencing.Conclusion Compared with the Sanger sequence, SNPscan is more lighter in workload, less time-consuming, higher-throughput, lower cost, and can get more meaningful mutations and reduce the false negative rates.
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Objective To investigate the prevalence and characteristics of GJB2 mutations in Uygur,Hui, Kazak and Kirgiz ethnic patients with non-syndromic hearing loss(NSHL)from the Xinjiang Uygur Autonomous Region of China.Methods With the permission,we collected 565 patients with moderately severe to profound sen-sorineural hearing loss,including Uygur,Hui,Kazak and Kirgiz ethnic minorities from 14 cities of Xinjiang.Pe-ripheral blood samples were obtained to extract genomic DNA.The SNP classification technology was for common pathogenic GJB2 gene mutations.ResuIts The pathogenic allele frequency of GJB2 gene were 10.16%(87/856 ), 15.85%(13/82),10.16%(13/128),1.56%(1/64)in the NSHL patients of Uygur,Hui,Kazak and Kirgiz minori-ties,respectively.And these differences were statistically significant (χ2 =8.140,P=0.043).c.235delc was only found in the Uygur and Hui with the allele frequency of 5.14 %(44/856)and 13.41 %(11/82),respectively.And c.35delG was found in Uyhur,Hui,Kazak and Kirgiz with allele frequencies were 3.15% (27/856),1.21% (1/82),8.59%(11/128)and 1.56% (1/64),respectively.ConcIusion GJB2 gene mutations had a higher incidence in Xinjiang NSHL patients,GJB2 gene mutation spectrum had differences in Uygur,Hui,Kazak and Kirgiz,c. 235delC the hotspot mutation region in Uygur and Hui nationalities NSHL patients,while c.35delG is the hotspot mutation region in NSHL patients of Uygur,Kazak and Kirgiz ethnicities.
ABSTRACT
Objective To investigate the prevalence of GJB2 ,SLC26A4 and mitochondrial DNA 12S rRNA m .1555A>G(mtDNA 1555A>G) mutations in Hui ethic group patients with nonsyndromic hearing loss (NSHL) from Northwest China .Methods A total of 420 peripheral blood samples were collected from unrelated Hui ethic group probands with NSHL in Northwest China .Amplified the target gene by polymerase chain reaction (PCR) af-ter extracting genomic DNA from whole blood .The mtDNA 1555A>G mutation was detected by PCR -Alw26I di-gestion ,then direct sequencing was used to the positive samples of mtDNA 1555A> G ,the coding region of GJB2 gene ,exon 8 and 19 of SLC26A4 gene .Results There were 11(2 .62% ) cases caused by mtDNA 1555A>G homo-zygous mutation in 420 patients with NSHL .There were 41(9 .76% ) cases including homozygote and compound het-erozygote ,caused by GJB2 gene mutation ,which was the most frequent deafness -related gene .The allel frequency of c .235delC accounted for 6 .90% ,as well as the most frequent(51 .33% ) mutational pattern in GJB2 gene .There were 20 patients(4 .76% ) were found carring two allel mutations in SLC26A4 gene .The allel frequency of c .919 -2A>G was 5 .0% ,accounting for a total of 68 .85% in all base alterations of SLC26A4 gene ,which was the major mutant form of SLC26A4 gene .Conclusion GJB2 gene is the most common deafness -gene in Hui ethnic group pa-tients with NSHL from Northwest China ,while c .235delC is the main mutant form ,and c .919-2A>G is the hot-spot mutation of SLC26A4 gene .Through this study we can provide the molecular epidemiology basis for Hui ethnic group patients with NSHL from Northwest China in genetic diagnosis ,genetic counseling and therapy by associated testing of three frequent hearing loss genes .