GPT genotyping by polymerase chain reaction and restriction fragment length polymorphism analysis

Polymorphism of GPT was investigated in blood samples from 241 unrelated Japanese individuals by PCR-RFLP analysis. Three common types were identified which agreed with those obtained by starch gel electrophoresis. The allele frequencies were GPT*1 = 0.604 and GPT*2 = 0.396. The population data fitted the Hardy-Weinberg law. The PCR-RFLP patterns of GPT were also demonstrated in semen, and the types coincided with those in the corresponding blood. The present method permitted GPT genotyping in bloodstains and semen stains stored for 20 years. The GPT system determined by PCR-RFLP can still be a useful supplement in medicolegal individualization of biological stains.