PCSK9 and metabolic process: Similarly, common polymorphisms associated with blood lipoprotein concentrations are often located in the genomic vicinity of genes associated with Mendelian disorders of lipoprotein metabolism, such as ABCG8, LCAT, APOB, LDLR, PCSK9, CETP, LPL, LIPC, and ABCA1. 57,58 We therefore reasoned that the phenotypic-genetic overlap might be a general tendency for rare and common diseases located at the same genetic locus.