Allele Frequencies of Apo(a) Pentanucleotide(TTTTA) Repeat Polymorphism

Hwang, Sang Hyun; Kim, Woo Yang; Chun, Sail; Min, Won Ki

Abstract

BACKGROUND: Lipoprotein(a) [Lp(a)] is an atherogenic lipoprotein that is assembled from a low density lipoprotein(LDL) and apolipoprotein(a) [apo(a)]. The variations in Lp(a) concentration tend to be inversely related to the number of kringle IV in apo(a) gene, but other polymorphisms [pentanucleotide(TTTTA) repeats, +93 C/T polymorphism, and Met/Thr polymorphism] of the apo(a) gene are also seems to be related to Lp(a) concentrations. The purpose of this study was to investigate the association of the pentanucleotide repeat polymorphism(PNRP) and Met/Thr polymorphism with the Lp(a) concentrations.
METHODS
We studied 197 healthy adults. For genotype analysis of the PNRP and the Met/Thr polymorphism, PCR was performed. Apo(a) phenotyping was performed by SDS-PAGE and immunoblotting. The Lp(a) concentrations were measured by ELISA method. More than two groups were compared using the Kruskal Wallis one-way analysis test. To establish a relationship between gene polymorphisms and Lp(a) concentrations, The linear regression test was performed.
RESULTS
Mean Lp(a) concentration was 25.3+/-21.5 mg/dL. Allele frequencies for PNRP, subjects with 8/8 genotype were 114(57.9%) and most frequently observed. The Lp(a) concentrations showed the tendency to decrease as the sum of alleles of PNR increased. Subjects with Met/Thr genotype were 119(60.4%), Met/Met genotype were 71(36.0%) and Thr/Thr genotype were 7(3.6%).
CONCLUSIONS
For PNRP, subjects with 8/8 genotype were 114(57.9%) and 8/8 genotype was the most frequently observed. Met/Thr genotype was most frequently observed.