Remarkably, some carrier states for recessive disease may raise the susceptibility for a common, complex trait as age progresses, as demonstrated by heterozygous SNVs observed in ABCA4, also known as ABCR, (MIM 153800), CFTR (MIM 167800), and LDLR (MIM 143890) genes leading to age-related macular degeneration, pancreatitis, and familial hypercholesterolemia, respectively [63, 99, 102–107]. This evidence concerns the gene ABCA4 and familial hypercholesterolemia.