alpha-L-fucosidase phenotyping in human placentae, semen and seminal stains

The polymorphism of alpha-L-fucosidase (Fu) was investigated in a Japanese population from samples of placentae and semen, using isoelectric focusing. The gene frequencies of placental types were Fu1 = 0.748 and Fu2 = 0.252, and those of seminal types were Fu1 = 0.739 and Fu2 = 0.261. The coincidence in the distribution between the placental and seminal types suggests that the Fu types occurring in placentae and in semen are controlled by the same Fu alleles. The Fu typing was possible in seminal stains stored at 4 degrees C for up to 9 weeks, at room temperature for up to 7 weeks and at 37 degrees C for up to 4 weeks. The Fu types were still detectable at semen dilutions of up to 1:4. This polymorphism would provide a useful genetic marker for the medicolegal grouping of seminal stains.