ApoE genotype affects allele-specific apo[a] levels for large apo[a] sizes in African Americans: the Harlem-Basset Study.
The genetic variability of apolipoprotein E (apoE) influences plasma lipoprotein levels, and allele frequencies differ between African Americans and Caucasians. As African Americans have higher lipoprotein [a] (Lp[a]) levels than Caucasians, we investigated the effects of the apoE gene on allele-specific apolipoprotein [a] (apo[a]) levels across ethnicity. We determined apo[a] sizes, allele-specific apo[a] levels (i.e., levels associated with alleles defined by size), and the apoE gene polymorphism in 231 African Americans and 336 Caucasians. African Americans, but not Caucasians, with the apo E2 genotype had lower levels of Lp[a] compared with those with the apo E4 genotype (9.6 vs. 11.2 nmol/l; P = 0.034, expressed as square root levels). Distribution of apo[a] alleles across apoE genotypes were similar between African Americans and Caucasians. Among African Americans with large apo[a], the allele-specific apo[a] level was significantly lower among epsilon2 carriers compared with epsilon3 or epsilon4 carriers (5.4 vs. 6.6 and 7.4 nmol/l, respectively; P < 0.005, expressed as square root levels). In contrast, there was no significant difference in allele-specific apo[a] levels across apoE genotypes among Caucasians. For large apo[a] sizes, apoE genotype contributed to the observed African American-Caucasian differences in allele-specific apo[a] levels.
Anuurad
Erdembileg
E
Department of Medicine, University of California, Davis, CA, USA.
Lu
Guijing
G
Rubin
Jill
J
Pearson
Thomas A
TA
Berglund
Lars
L
D001741:Black or African American / Q000235:genetics*; D000483:Alleles; D000704:Analysis of Variance; D001057:Apolipoproteins E / Q000235:genetics*; D053241:Apoprotein(a) / Q000097:blood*; D016009:Chi-Square Distribution; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008055:Lipids / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic
D001057:Apolipoproteins E; D008055:Lipids; D008074:Lipoproteins; D053241:Apoprotein(a)