LDLR and familial hypercholesterolemia: Familial hypercholesterolemia (FH), an autosomal dominant genetic disorder caused by mutations in Low-Density Lipoprotein Receptor (LDLR), ApoB or Proprotein Convertase Subtilisin/kexin type 9 (PCSK9), is characterized by life-long exposure of very high levels of LDL-C and early cardiovascular disease.