The Study On Polymorphism Of NUDT15 Gene Related To Thiopurine Metabolism In Dai Children Of Yunnan Province

Objective:we will study the genetic polymorphisms of NUDT15 of healthy Dai nationality children in Yunnan province,and analyze the frequency distribution of alleles,in order to provide data support for the comparative analysis of gene polymorphism between ethnic minorities and Han nationality.Methods:A total of 152 healthy children(between 0.2 and 14 years old))from families belonging to Dai nationality in three generations in Yunnan Province were collected.3ml of peripheral blood was collected from each subject.The exon 1-3 of NUDT15 gene was detected by DNA extraction,primer design,PCR amplification,PCR product purification and gene sequencing.The median was used to represent age,the genotypes and alleles of the polymorphic loci were counted directly,the sample number among the genotypes was analyzed by Hardy Weinberg equilibrium law,and the frequency and number between groups were compared by chi-square test.Results:1.A total of 152 blood samples from healthy children(between 0.2 and 14 years old)of Dai nationality in Yunnan Province were collected.Among the blood samples of NUDT15 Exonl,A total of one variant was found in the 145 samples successfully detected,which is rsl86364861(c.52G>A,encoding P.vall8 Ile),).The mutation was found in 2 children,accounting for 1.38%,and the wild type without normal mutation was found in 143 cases,accounting for 98.62%.2.Among the healthy children of Dai nationality in Yunnan Province,149 cases of NUDT15 Exon 2 were detected successfully,and no mutant genotype was found.3.Among the healthy children NUDT15 Exon 3 of the Dai nationality in Yunnan,112 cases were successfully detected,including 69 boys and 43 girls,with a median age of 5 years(between 0,2 and 14 years old).A total of one gene variant was found,which was rs116855232(c.415C>T,encoding p.Arg139cys),of which 102 cases were wild type,accounting for 91.07%of the total,there were 10 cases of rs116855232,accounting for 8.93%of all cases,and 0 cases of TT.4.Among the collected NUDT15 rs116855232 mutations,wild type CC accounted for 91.07%,heterozygous mutation CT genotype 10 cases,accounting for 8.93%,homozygous mutation TT genotype 0 cases,of which the risk allele frequency was 4.5%.Conclusion(s):1.Two common variants of NUDT15 gene,rs116855232 and rs186364861,were found in the samples of healthy children of Dai nationality in Yunnan Province,compared with NUDT 15 gene database and related literature,no new mutation was found.2.The allele frequency of rs116855232 risk in healthy children of Dai nationality in Yunnan is low.However,the frequency of NUDT15 rs116855232 genotype and risk allele was similar to that of healthy children of Yi nationality in Yunnan province.3.This study found that the probability of homozygous mutation in rs116855232 of healthy children of Dai nationality in Yunnan was very low.4.It is suggested that the TT mutation of NUDT15 rs116855232 homozygote in Dai ALL children should be appropriately reduced.If conditions permit,other NUDT 15 gene variants can be detected together to improve the sensitivity and specificity of predicting thiopurine-induced leukopenia.5.The peripheral blood samples of healthy children of Dai nationality in Yunnan Province showed that different genotypic mutations of NUDT 15 Exon 1-3 had nothing to do with sex.6.The NUDT15 gene polymorphism data obtained in this study not only supplement the vacancy of Chinese Dai data in the database,but also provide data support for the next comparative analysis of genetic polymorphism of NUDT15 gene in Han nationality and other ethnic minorities in China.