Observation and analysis of STR loci mutation among 1 786 cases of paternity test in Guangxi area / 重庆医学

ABSTRACT

Objective To observe and analyze the mutation characteristics of 17 STR loci among the paternity test cases in Guangxi area .Methods Among 1 786 cases of non—exclusion parentage ,1 430 cases were parental triplet and 356 cases were uniparental diad ,1 001 persons were Han people ,2 102 persons were Zhuang people and 113 persons were other ethnic group in the parents .The genome DNA was extracted by Chelex-100 method .17 short tandem repeat (STR) loci were detected by Power Plex ? 18D System Kit .The paternity testing containing mutant STR loci were screened out from 1786 cases .The locus-specific ,specificity of paternal and maternal ,and allele-specific mutation rates were observed and analyzed ,respectively .The characteristics of the muta-tions were studied .Results In total ,75 mutations events were observed at 16 of the 17 loci .Among them ,73 (97 .34% ) times were one step mutation ,onece(1 .33% ) was two—step mutation ,and once(1 .33% ) was three—step mutation ,no mutation was found at the TPOX locus .The mutation rates ranged 0 .031 1% —0 .404 2% ,and the mean mutation rate was 0 .145 8% .The proportion of the paternal mutations and the maternal mutations was 5 .41 .0 ,the difference had statistical significance(P0 .05) .Conclusion STR loci mutation is common phenomenon in paternity test .The data of STR loci mutations should be constantly accumulated for selecting the genetic characteristics in line with the Guangxi population and the genetic markers of STR loci with high identification ability to ensure ac-curate and reliable identification results .