A Comparative Study Of Common Deafness Gene In Deaf People From Sole Minority Nationalities And The Newborn With High Risk In Gansu Province By SNPscan And Sanger Sequence

Objective:To compare the advantages and disadvantages of SNPscan and Sanger sequence which were both used to detect the common deafness gene mutations in non-syndromic hearing loss （NSHL） from sole minority nationalities in Gansu Province.Methods:Peripheral blood samples were obtained form Dongxiang, Yugur and Bonan 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:1、We use the SNPscan to screen the mutation of GJB2 gene,mtDNA A1555G and mtDNA C1494T, SLC26A4 gene of non-syndromic deafness patients from Gansu Province.The mutation rate of these three genes was 23.18%（35/151）, the mutation rate of Dongxiang, Yugu, Baoan was 21.31% （26/122）,54.54% （6/11）,16.67% （3/18）, respectively.2、The causative mutation frequency of Dongxiang was 11.48% （14/122）, the allele frequency was 17.21% （42/244）. c.299-300delAT was the mutation hotspots of ethnic Dongxiang which was 4.51% （11/244）. The causative mutation frequency of Yugurs was 45.45% （5/11）, the allele frequency was 59.09%（13/22）, c.35delG was the mutation hotspots of ethnic Yugurs which was 18.18% （4/22）. The causative mutation frequency of Bonan was 5.56%（1/18）, the allele frequency was 11.11% （4/36）, c.109G> A was the mutation hotspots of ethnic Yugurs which was5.56%.3、The causative mutation frequency of GJB2 gene in Dongxiang was 9.83%（12/122）, the allele frequency was 13.11% （11/244）, c.299₃00delAT was the mutation hotspots of ethnic Dongxiang which was4.51% （11/244）. The causative mutation frequency of GJB2 gene in Yugurs was 36.36% （4/11）, the allele frequency was 40.91% （9/22）, c.35delG was the mutation hotspots of ethnic Yugurs which was 18.18% （4/22）. The causative mutation frequency of GJB2 gene in Bonan was5.56%（1/18）, the allele frequency was 11.11% （4/36）, c.109G> A was the mutation hotspots of ethnic Yugurs which was5.56%.Conclusion:1、In this study, we used SNPcan to screen the 115 common mutation of GJB2, SLC26A4, mtDNA gene in Gansu Dongxiang, Yugu, Bonan 151 cases with non-syndromic sensorineural hearing loss. Comfired that the SNPscan method was higher accuracy in gene detection, higher-throughput, higher efficiency and lower cost.It was suitable to used to screen the mutation of deafness gene from sole minority nationalities in Gansu Province.2、The hot mutation had a certain difference among Dongxiang, Yugur and Bonan nationalities NSHL patients in Gansu Province. The mutation frequency of GJB2 gene was the highest, followed by Yugur, the Bonan was lowest. But there was no statistically significant difference; The mutation of SLC26A4 gene was only detected in Dongxiang, The mutation of mtDNA gene was only detected in Yugurs.3、Compared with the traditional Sanger sequence which only detects the second exon of GJB2 gene, SNPscan is more workload lighter, shorter time-consuming, higher-throughput, lower cost, higher detection rate, can get more meaningful mutations,reduce the false negative rate, Thus, before making the sequencing of all exons the SNPscan seem more meaningful.4、SNPscan method can detect single nucleotide copy number variation, while traditional Sanger sequence can not.The copy number variation may lead to deafness. Compared with the traditional Sanger sequence, SNPscan method may improve the positive rate of disease diagnosis.Objective:To compare the advantages and disadvantages of SNPscan and Sanger sequence which was both used to detect the common deafness gene mutations in the newborns with high risk in the NICU of Gansu Province.Methods:Peripheral blood samples were obtained from neonatal intensive care unit of Lanzhou university second hopital, the Gansu Provincial Hospital, Childen’s Hospital of Gansu Province, Childen’s Hospital of Tianshui to extract genomic DNA. SNPscan was used to detect the 115 mutations of the common pathogenic GJB2 gene, SLC26A4 gene and mtDNA gene.Results:1、We used the SNPscan to screen the 115 common mutations of GJB2 gene,mtDNA1555A> G and mtDNA1494C>T, SLC26A4 gene of 100 cases of neonatal intensive care unit in Gansu Province. The mutation rate of these three genes was 14%. We also found that there were two cases of neonatal carrying A1555G homozygous mutation, six cases of c.109G> A, one c.919-2A> G, one c.235de1C and c.919-2A>G, one c.1174A> T, one c.2027T> A, one c.299₃00delAT, one c.571T> C heterozygous mutation.2、The causative mutation rate f the 100 cases in NICU was 2%,the allele frequency was 8.5% （17/200）. The allele frequency of c.109G> A was highest which was 3% （6/200）, followed by A1555G, c.919-2A> G, c.235de1C, c.1174A> T, c.2027T> A, c.299₃00delAT, c.571T> C, the allele frequency was 2% （4/200）,1% （2/200）,0.5% （1/200）,0.5%（1/200）,0.5%（1/200）,0.5% （1/200）,0.5%（1/200）,respectively.Conclusion:1、We used the SNPscan to screen the 115 common mutation of GJB2 gene,mtDNA A 1555G and mtDNA C1494T, SLC26A4 gene of 100 cases of neonatal intensive care unit in Gansu Province we also found that there are two cases of neonatal carrying A1555G homozygous mutation, six cases of c.109G> A, one c.919-2A>G, one c.235de1C and c.919-2A>G, one c.1174A> T, one c.2027T> A, one c.299₃00delAT, one c.571T> C heterozygous mutation. The mutation rate of these three common genes was 2%. The allele frequency of the 100 cases of ICU was 8.5%.2、Compared with the previous research, the SNPscan has lower testing costs, more speeder, higher-throughput,easyer operation,greatly improving the efficiency of screening in deafness genes. It was suitable to used to screen the mutation of deafness gene from the newborn of NICU in Gansu Province.