The group-specific component (Gc) subtypes were determined by isoelectric focusing and immunoblotting. The gene frequencies in the Swedish Lapps were Gc1F = 0.412, GcIS = 0.367 and Gc2 = 0.221, which was significantly different from the frequencies found in Finns and in the populations of northern and central Sweden (p < 0.001). The gene frequencies in the Swedish Lapps, although similar to those in Asiatic populations, are probably not reflecting an Asiatic influence, since the accumulated genetic information on the Swedish Lapps suggests that founder effect and genetic drift are to a large extent responsible for the peculiar gene pool of the original Lapp population.