LDLRAP1 and familial hypercholesterolemia: Heterozygous familial hypercholesterolemia (HeFH) affects about 1 in 311 individuals, whereas the homozygous form (HoFH), caused by biallelic pathogenic variants in LDLR, APOB, PCSK9 or LDLRAP1, is far rarer, with an estimated prevalence of 1 in 250,000–360,000 [13].