Polymorphisms Analysis Of Short Tandem Repeat Loci D18S53, D18S59, D18S488 In Tianjin Han Nationality In China

Objective Edwards Syndrome is the second trisomy syndrome, the incidence is 1/6 000, the clinical manifestations is multiple malformations. About 30% can live to 3 months, less than 10% can live to 1 year,1-2% can live to 10 years old. Trisomy syndrome can not be treated, efficenty way to reduce it is provent its birth by prenatal diagnosis. Traditional prenatal diagnosis is chromosome analysis, but it needs long time, high technically demanding and not suitable for large sample testing. There is an urgent need for rapid prenatal diagnosis of chromosome aneuplodies.To investigate the genetic polymorphisms of 3 STR loci on chromosome 18: D18S53, D18S59, D18S488 in Han population of Tianjin regain and construct a preliminary database for genetic analyse, and the aim of the study was to develop a accurate, simple and rapid technique of chromosome aneuplodies diagnosis in clinic.Methods 369 DNA samples were extracted from the peripheral blood of unrelated individuals in Tianjin regain, and then amplified with three short tandem repeats markers specific to chromosome 18, which included D18S53, D18S59 and D18S488 loci, by QF-PCR. Amplification products were electrophoresed by ABI PRISM 377 sequencer and analysed by GeneScan 3.1 sofrware. For the 3 STRs, the distributions of genotypes were tested with Hardy-Weinberg equilibrium. Using PowerStatsV12 software genetical analysis was performed to conclude some data of population genetics such as the heterozygosities, the polymorphism information contents, the probabilities of discrimination power and the probabilities of exclusion, and so the cumulative data of D18S53, D18S59 and D18S488 loci.Results 1. All of the experiment 369 examples appeared as a normal diploidy. No triploidy were detected.2. The alleles of the D18S53, D18S59 and D18S488 loci were observed in the 369 samples, whose frequencies of the genotypes were in accord with Hardy-Weinberg equilibrium.3. The heterozygous percentages observed from these three loci were 76.7%, 76.2%,70.5%, the polymorphism information contents were 0.80,0.73,0.65, the probabilities of discrimination power were 0.947,0.907,0.851, and the probabilities of exclusion were 0.539,0.530,0.435.4. The cumulative polymorphism information contene, probability of discrimination power and probability of exclusion of D18S53, D18S59 and D18S488 loci were 0.9811,0.999265579,0.87758145.Conclusions 1. D18S53, D18S59 and D18S488 loci were in accord with Hardy-Weinberg equilibrium in individuals of Han nationality in Tianjin areas.2. D18S53, D18S59 and D18S488 loci were high heterozygous, high polymorphism information contents, high probabilities of discrimination power. They were properly genetic markers on chromosome 18.3. The genetic polymorphisms of D18S53, D18S59 and D18S488 loci were high, and all of them were high valuable in the application of forensic medicine and population genetics.4. Amplifying D18S53, D18S59 and D18S488 loci with QF-PCR technique is reliable for polymorphism analysis and chromosome aneuplodies diagnosis, the result is accurately. This method has high clinical values.