LDLR and Hypercholesterolemia: Known genes related to hypercholesterolemia include low density lipoprotein receptor (LDLR) [2], proprotein convertase subtilisin/kexin type 9 (PCSK9) [3], apolipoprotein B (APOB) [4] and low density lipoprotein receptor adaptor protein 1 (LDLRAP1) [5], among others.