Genetic basis for multimodal relationship between apolipoprotein (a) size and lipoprotein (a) concentration in Mexican-Americans.
The reported general inverse relationship between apolipoprotein (a) (apo(a)) size and plasma lipoprotein (a) (Lp(a)) concentrations was further characterized using 927 samples taken from members of 42 Mexican-American families. When all samples were displayed in a scatter plot of apo(a) size versus natural log of Lp(a) concentration, the expected inverse relationship was observed (r2 = 0.24). However, the scatter plot revealed a multimodal pattern with at least two distinct modes of the inverse relationship between apo(a) size and Lp(a) concentration. Plots of 148 single-banded samples also showed the multimodal pattern, indicating that this pattern did not result from a difference between double- and single-banded samples. Also measured was the Lp(a) concentration associated with each of 508 apo(a) isoforms in samples from 254 double-banded phenotype individuals. These separated isoforms also showed the multimodal pattern. Using pedigree information, 29 different alleles were identified which were found in three or more family members. About 85% of variation in Lp(a) was explained by allele information, suggesting a genetic basis for the multimodal pattern. Thus, the data demonstrate at least two series of apo(a) alleles that have distinct relationships between apo(a) size and Lp(a) concentration.
Rainwater
D L
DL
Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas 78228-0147, USA.
D000483:Alleles; D001054:Apolipoproteins A / Q000097:blood / Q000235:genetics*; D002318:Cardiovascular Diseases / Q000097:blood / Q000235:genetics; D006801:Humans; D017270:Lipoprotein(a) / Q000097:blood / Q000235:genetics*; D017058:Mexican Americans / Q000235:genetics*; D010641:Phenotype; D012307:Risk Factors
D001054:Apolipoproteins A; D017270:Lipoprotein(a)