APOE and familial hypercholesterolemia: One of the best known cause of HC is familial hypercholesterolemia (FH)# 143890, a genetic disorder with an autosomal codominant inheritance pattern, due to a monogenic defect in LDL receptor (LDLR), apolipoprotein B (APOB), Proprotein convertase subtilisin/kexin type 9 (PCSK9), or apolipoprotein E (APOE) genes, involved in the LDL receptor endocytic and recycling pathways.