Even though the R46L variant was present in 3% of our FH population, carriers of this polymorphism showed attenuated effect of the low density lipoprotein receptor mutation on parameters, such as low density lipoprotein cholesterol, apolipoprotein B, total cholesterol, and non-high density lipoprotein.
1130 unrelated subjects with molecularly defined FH were screened for mutation R46L in the PCSK9 gene and cell culture experiments were performed to study the effect of high concentrations of low density lipoprotein (LDL) on the binding of PCSK9 to the LDL receptor (LDLR).
We measured plasma PCSK9 concentrations in healthy men with a PCSK9 (proprotein convertase subtilisin/kexin type 9) loss-of-function variant (p.R46L), in statin-treated patients with a clinical diagnosis of familial hypercholesterolemia (FH) and carrying a PCSK9 gain-of-function mutation (p.D374Y), and in statin-treated patients with FH due to different genetic causes.