Lipoprotein(a) is a macromolecular complex in human plasma which represents a quantitative genetic trait with a heritability of 0.7 or higher. Lipoprotein(a) is composed of an LDL-like particle in which apoB (107730) is covalently bound by a single disulfide bond to apolipoprotein(a). Apo(a) has been demonstrated to be the main determinant of the quantitative Lp(a) trait. Variation in the number of plasminogen (PLG)-like kringle (K) IV type 2 tandem repeats in the apo(a) gene is inversely correlated to Lp(a) plasma levels in all populations studied. Several polymorphisms in the Lp(a) gene have been found to affect the apo(a) concentration level (summary by Ogorelkova et al., 1999). [from
OMIM]