sentences:  Lp(a) plasma concentrations are highly heritable and mainly controlled by the LPA gene located on chromosome 6q26-27.Apo(a) proteins vary in size due to a size polymorphism [KIV-2 VNTR], which is caused by a variable number of kringle IV repeats in the LPA gene.This size variation at the gene level is expressed on the protein level as well, resulting in apo(a) proteins with 10 to more than 50 kringle IV repeats (each of the variable kringle IV consists of 114 amino acids).