Apolipoproteins E and CI are the predominant components of triglyceride-rich lipoproteins. The genes are located in one gene cluster and both are polymorphic. Three allelic (ε2, ε3 and ε4) polymorphisms of the APOE gene influence plasma cholesterol levels. The distribution of these alleles differ between ethnic groups. PCR genotyping was used to determine the APOE and APOCI allele incidence in a representative group of 653 probands (302 men and 351 women) of Czech origin. The observed relative frequencies for the ε2, ε3 and ε4 alleles were 7.1 %, 82.0 % and 10.9 %, respectively, and are similar to other middle European populations. APO ε4 carriers have the highest and APO ε2 carriers the lowest levels of plasma total cholesterol (p<0.0001) and LDL cholesterol (p<0.0001). The frequency of the insertion (I) allele (HpaI restriction site present) of the APOCI polymorphism was 18.5 %. APOCI I/I homozygotes have the highest level of triglycerides (p<0.003). An almost complete linkage disequilibrium of the insertion allele of APOCI with the APOE alleles ε2 and ε4 has been detected and suggests that the deletion in the APOCI gene probably follows the deriving of all three APOE alleles on the APO ε3 allele background., J. A. Hubáček, J. Piťha, V. Adámková, Z. Škodová, V. Lánská, R. Poledne., and Obsahuje bibliografii