Ancestral Variation in Lp(a): Epidemiology, Isoform Diversity, and Testing

This review aims to explore the epidemiology of lipoprotein(a) [Lp(a)] by its structural and genetic make-up variation amongst ancestry groups.

Lipoprotein(a) [Lp(a)] is a genetically determined lipoprotein particle, causally implicated in atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve stenosis (CAVS). Given its genetic basis, studies have shown marked ancestry-related differences in different races and ethnicities. Lp(a) plasma concentrations vary by more than 100-fold among individuals, primarily due to LPA gene polymorphisms and the number of kringle-IV type 2 (KIV2) repeats, which define apolipoprotein(a) [apo(a)] isoform size. Individuals of African descent have the highest median concentrations, followed by South Asians, with Hispanics/Latinos and East Asians having lower levels. Admixed populations display heterogeneity reflecting genetic ancestry. Despite differences in absolute levels, the relative ASCVD risk per unit increase in Lp(a) is consistent across groups, highlighting the universal atherogenicity of elevated Lp(a). Small apo(a) isoforms are associated with higher Lp(a) concentrations and risk, though isoform size is mainly a surrogate for Lp(a) burden. Despite a strong genetic basis and disproportionate burden in some populations, ancestry-specific testing guidelines are limited and testing rates remain low. Therapies targeting LPA transcription are in development, with outcome trials underway. Integrating ancestry-informed perspectives with universal risk principles is essential for equitable prevention and treatment. Routine, one-time Lp(a) testing enables cost-effective early risk stratification as Lp(a)-directed therapies emerge.