PON1 and familial hypercholesterolemia: In this study, we report on the role of PON1 coding sequences of single nucleotide polymorphisms (SNPs) rs662 (c.575A > G; p.Gln192Arg) and rs854560 (c.163T > A (p.Leu55Met) in relation to resultant paraoxonase and arylesterase activity in hypercholesterolemia patients with mutated LDLR. The structural and functional aspects of these SNPs have also been studied to explore how different allozymes affect and mediate the paraoxonase and arylesterase activities of the enzyme.