LDLR variant classification for improved cardiovascular risk prediction in familial hypercholesterolemia

Area of Science:

• Genetics
• Cardiovascular Medicine
• Biochemistry

Background:

• Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated LDL cholesterol and premature coronary artery disease (CAD) risk.
• Current classification of LDL receptor gene (LDLR) variants may not fully capture individual variability in LDL cholesterol and CAD risk.
• A novel approach using variant-specific LDL cholesterol percentiles is proposed to better assess LDLR variant severity.

Purpose of the Study:

• To develop and validate a novel method for classifying LDLR variants based on their impact on LDL cholesterol levels.
• To assess the association between these refined variant classifications and coronary artery disease (CAD) risk.
• To compare the precision of this new classification system with traditional methods for FH patient risk stratification.

Main Methods:

• Screening of 456 LDLR variants in 35,067 participants from the Dutch FH cascade screening program.
• Derivation of sex- and age-specific LDL cholesterol percentiles for each LDLR variant carrier.
• Grouping carriers into distinct LDL cholesterol strata and comparing CAD risk using Cox proportional hazard models.

Main Results:

• 12,485 LDLR variant carriers were identified, exhibiting a 5-fold higher CAD risk than non-carriers.
• Coronary artery disease (CAD) risk increased progressively across LDL cholesterol strata, with hazard ratios ranging from 2.2 to 12.0.
• Carriers of class 1 and non-class 1 LDLR variants showed significantly increased CAD risks (7.3-fold and 3.9-fold, respectively).

Conclusions:

• A refined approach for classifying LDLR variants based on LDL cholesterol impact has been developed.
• This method allows for more precise, genotype-specific CAD risk estimation in FH patients.
• The proposed classification improves upon traditional methods for stratifying FH patient risk.