Investigations on the polymorphism of sperm diaphorase in man. Evidence for a third common allele, SD.

The polymorphism of sperm diaphorase (SD) was investigated in 141 unrelated persons from Hessen, Germany, by high voltage thin-layer agarose gel electrophoresis (Age) and thin-layer isoelectric focusing on polyacrylamide gel (Pagif). In addition to the three known common phenotypes SD 1, 2-1, and 2, two further phenotypes with the preliminary designation SD 3-1 and SD 3-2 were discovered. This polymorphism can thus be explained in terms of three alleles, SD1, SD2, and SD3 segregating at an autosomal locus. The allele frequencies calculated from the five different phenotypes SD 1, 2, 2-1, 3-1, and 3-2 are: SD1 = 0.7553, SD2 = 0.2234, and SD3 = 0.0213. As we also found SD activity in female reproductive tract tissues (ovaries, oviducts, uterus), the term 'gonadal diaphorase' (GD) appears to be applicable.