出版社：American Society for Biochemistry and Molecular Biology
摘要：Apolipoprotein [a] (apo[a]) gene size is a major predictor oflipoprotein [a] level. To determine genetic predictors of allele-specificapo[a] levels beyond gene size, we evaluated the upstream C/Tand pentanucleotide repeat (PNR) polymorphisms. We determinedapo[a] sizes, allele-specific apo[a] levels, and C/T and PNRin 215 Caucasians and 139 African Americans. For Caucasians,apo[a] size affected allele-specific levels substantially greaterin subjects with apo[a] < 24 K4; for African Americans, thesize effect was smaller than in Caucasians, <24 K4, but didnot decrease at higher repeats. In both groups, the level decreasedwith increasing size of the other allele. Controlling for apo[a]sizes, PNR decreased allele-specific apo[a] levels in Caucasianswith increasing PNR > 8. In a multiple regression model,apo[a] allele size and size and expression of the other apo[a]allele (and PNR > 8 for Caucasians) significantly predictedallele-specific apo[a] levels. For a common PNR 8 allele, predictedvalues were similar in the two ethnicities for small size apo[a].Allele-specific apo[a] levels were influenced by the other allelesize and expression. Observed differences between Caucasiansand African Americans in allele-specific apo[a] levels wereexplained for small apo[a] sizes by the other allele size andPNR; the ethnicity differences remain unexplained for largersizes.Supplementary key words lipoprotein [a] • African Americans • genotyping • polymorphism • apolipoprotein [a] • pentanucleotide repeat
