Correlation between clinical classification and genetic analysis of familial hypercholesterolemia in premature coronary artery disease in a cohort of Egyptian patients.

Background: Familial Hypercholesterolemia (FH) is a major risk factor for premature Coronary Artery Disease (CAD). Genetic testing is the gold standard for FH diagnosis. The purpose of this Observational Analytical Cross-sectional study was to estimate the proportion of genetically confirmed Familial Hypercholesterolemia in Patients with premature Coronary Artery Disease in a cohort of Egyptian patients.

Methods: Next generation sequencing (NGS) was conducted for 7 genes (LDLR, PCSK9, APOB, APOE, ABCG5, ABCG8 and LDLRAP1) commonly associated with FH in 94 patients with Premature CAD from 2 tertiary hospitals in Cairo and Alexandria, Egypt. Individuals were clinically assessed using the Dutch Lipid Network criteria and genetically-confirmed FH prevalence was analyzed.

Results: Fourteen patients had pathogenic or likely pathogenic mutations in LDLR, APOB, PCSK9 and LDLRAP1 genes. Three patients had homozygous autosomal dominant FH and another 3 patients had autosomal recessive hypercholesterolemia. In addition, 10 patients had rare variants of uncertain significance in LDLR, APOB, APOE, ABCG5 and ABCG8 genes.

Conclusions: The prevalence of genetically confirmed FH in premature CAD (PCAD) patients in this study was found to be 14.89%. The Dutch Lipid Clinic Network (DLCN) scoring system is suggested as a good screening tool for familial hypercholesterolemia but confirmatory genetic testing is essential for the accurate diagnosis and management of the patients. In Egypt, the high rate of consanguinity contributes to the high prevalence of both homozygous autosomal dominant and recessive FH.