RESUMO
Prior to the introduction of any DNA marker as a tool for person identification and paternity test in certain ethnic groups, a population genetic database should be constructed. Using multiplex primers in single tube polymerase chain amplification, 5 loci of unrelated genes in the PM Amplitype kit (Perkin Elmer) were studied in two Thai population groups: 228 DNA samples were extracted from blood collected at the Borai rural area in Trat province; another 123 DNA samples were collected at the outpatient clinic, Department of Forensic Medicine, King Chulalongkorn Memorial Hospital, Bangkok. Analysis of alleles and genotypes was performed after reversed dot blot hybridization of PCR products to allelic sequence specific probes immobilized on the membrane strip followed by nonradioisotopic detection according to the manufacturer's protocol. Population genetic statistic parameters including discrimination power (DP), the probability of matching (PM), power of exclusion for trio (PE trio) and typical paternity index (PI typical) were computed. Both Thai population groups showed no significant deviation from the Hardy Weinberg Expectation (HWE). The combined DP of all 5 loci in the PM Amplitype markers was 0.993636 for rural Thais and 0.994409 for Thais from Bangkok. The combined PM for rural Thais and those living in Bangkok was 0.006364 and 0.005591, respectively. The combined PE trio was 0.696825 and 0.698875 in both Thai population groups and the combined PI typical values were < 1.0. In conclusion, person identification using PM Amplitype DNA markers was efficient and satisfactory within certain limits. Hence, the application of PM Amplitype DNA markers for paternity tests should be cautiously considered and applied in combination with other parameters.