Nonsynonymous SNPs in homologous to plasminogen deficiency mutants represent novel null apo(a) alleles.

Plasma lipoprotein (a) [Lp(a)] levels are largely determined by variation in the gene, which codes for apo(a). Genome-wide association studies (GWASs) have identified nonsynonymous variants in that associate with low Lp(a) levels, although their effect on apo(a) function is unknown. We investigated two such variants, R990Q and R1771C, which were present in four null Lp(a) individuals, for structural and functional effects.