Familial hypercholesterolemia (FH) is an autosomal dominant disorder of lipid metabolism associated with premature atherosclerosis and increased cardiovascular risk. Over 3,000 variants in LDLR, APOB, and PCSK9 have been identified in FH patients; however, <10% of these have been functionally proven to cause disease. The recent ACMG/AMP guidelines for standardized variant interpretation in Mendelian disorders a...