Genetic polymorphisms affecting the phenotypic expression of familial hypercholesterolemia

Area of Science:

• Genetics
• Cardiovascular Medicine
• Metabolic Disorders

Background:

• Familial hypercholesterolemia (FH) exhibits variable clinical expression despite identical LDL receptor (LDL-R) mutations.
• This variability may stem from environmental factors and genetic modifiers of lipoprotein metabolism.

Purpose of the Study:

• To investigate the impact of common genetic polymorphisms on lipid profiles and coronary artery disease (CAD) risk in heterozygous FH patients.
• To identify specific genetic variants that modify the lipid phenotype and cardiovascular risk in FH.

Main Methods:

• Analyzed polymorphisms in genes including Apo E, MTP, Apo B, Apo A-V, HL, FABP-2, LPL, and ABCA1 in 221 FH index cases and 349 relatives.
• Correlated genotypes with plasma lipid levels (LDL-C, HDL-C, triglycerides) and CAD status.

Main Results:

• Significant independent effects of Apo E, MTP, and Apo B on LDL-C; HL, FABP-2, and LPL S447X on HDL-C; and Apo E and Apo A-V on triglycerides were observed.
• FABP-2 54TT genotype was more prevalent in CAD+ subjects, while ABCA1 219RK/KK genotypes were less prevalent.
• Independent predictors of increased CAD risk included male sex, age, hypertension, LDL-C, and FABP-2 54TT genotype; ABCA1 219RK/KK genotypes were protective.

Conclusions:

• Common genetic variants significantly influence lipid phenotypes in heterozygous FH.
• Specific polymorphisms in FABP-2 and ABCA1 are associated with CAD risk in FH patients, highlighting their role as genetic modifiers.