<Original Article> Phenotyping of Gamma-Glutamyl Transferase in Human Semen, the Prostate and Seminal Stains

Polymorphism of gamma-glutamyl transferase (GGT) was investigated in semen samples from 744 Japanese males. Using a simple method of starch gel electrophoresis, 3 common types (GGT 1, GGT 2-1 and GGT 2) were observed. The population data fitted the Hardy-Weinberg law. The allele frequencies were: GGT*1=0.591 and GGT*2=0.409. Among the male reproductive organs, only the prostate exhibited the 3 electrophoretic patterns corresponding to the seminal GGT types. Thus, it was concluded that the seminal GGT originates from the prostate. Reliable phenotyping was possible on post coital vaginal contents and also on 1-year-old senminal stains. The GGT system can provide a useful genetic marker for medicolegal individualization of seminal stains.