Genetic polymorphism of the C4 component of human complement in the Slovak population.

: The distribution of C4 phenotypes and gene frequencies were studied in 104 genetically unrelated persons of Slovakia using high-voltage agarose gel electrophoresis with subsequent immunofixation. Five C4A alleles and three C4B alleles were detected. The gene frequencies were as follows: A2 = 0.0576, A3 = 0.7644, A4 = 0.0336, A6 = 0.0625, AQ0 = 0.817, B1 = 0.7836, B2 = 0.1009, BQ0 = 0.1153. The C4AQ0 and C4BQ0 alleles established by densitometry appeared in the Slovak population in 16.34% and 23.07%, respectively.