Lipoprotein (a) and apolipoprotein (a) phenotypes in healthy Macedonian children

Background: Plasma levels of lipoprotein(a) [Lp(a)] are determined largely by genetic variation in the gene encoding apolipoprotein(a) [apo(a)], the unique protein component of Lp(a). High plasma levels of Lp(a) increase the risk of premature atherosclerosis. However, the association of apo(a) phenotypes with the development of these diseases remains largely unexplored. Objectives: Determination of Lp(a) levels and apo(a) isoforms (phenotypes) in 100 (51 boys, 49 girls) Macedonian healthy children aged 9-18. Methods: We used 3-15 % gradient SDS-PAGE for separation of apo(a) isoforms. According to the different apo(a) electrophoretic mobilities, Apo(a) was classified into five single and respective double-band phenotypes. Results: Each individual expressed a single (homozygotic), double band (heterozygotic) or no band (null phenotype). The apo(a) phenotype frequencies revealed that the frequency of single-band phenotype expression (64 %) was higher than that of double bands (32 %) and that the frequency of phenotypes representative of low molecular weight was very low (4 %). The most frequent phenotype was S4 (42.65 %). The distribution of plasma Lp(a) levels was skewed, with the highest frequencies at low levels. The mean Lp(a) concentration was 11.95 (SD of 5.98 and median of 9.62 mg/dL). We did not rind differences in the mean and median plasma Lp(a) levels between boys and girls (p>0.05). A strong inverse relationship was found between the apparent molecular weight of apo(a) phenotypes and plasma Lp(a) concentration (r= -0.4257). Conclusions: Determination of Lp(a) levels and apo(a) phenotypes in children, may help in preventing and reducing the risk of atherosclerotic development (Tub. 6, Ref. 32). Full Text (Free, PDF) www.bmj.sk.