The genetics of familial hypercholesterolemia and emerging therapies.

Familial hypercholesterolemia (FH) results in very high levels of atherogenic low-density lipoprotein (LDL) cholesterol from the time of birth. Mutations of the genes encoding for the LDL receptor, apolipoprotein B and proprotein convertase subtilisin/kexin type 9, are causes for this autosomal dominant inherited condition. Heterozygous FH is very common, while homozygous FH is rare. Affected individuals can experience premature cardiovascular disease; most homozygous patients experience this before the age of 20 years. Since effective LDL cholesterol lowering therapies are available, morbidity and mortality are decreased. The use of statins is the first choice in therapy; combining other lipid-lowering medications is recommended to lower LDL cholesterol sufficiently. In some cases, lipoprotein apheresis is necessary. In heterozygous FH, these measures are effective to lower LDL cholesterol, but in severe cases and in homozygous FH there remains an unmet need. Emerging therapies, such as the recently approved microsomal triglyceride transfer protein inhibitor and the apolipoprotein B antisense oligonucleotide, might offer further options for these patients with very high cardiovascular risk. Early diagnosis and early treatment are important to reduce cardiovascular events and premature death.