Genetics of early-onset coronary artery disease: from discovery to clinical translation.

PURPOSE OF REVIEW: This review is a comprehensive update on recent discoveries on the genetics of early-onset coronary artery disease (EOCAD), and how those findings can be translated to advance its medical management. RECENT FINDINGS: To date, a total of 266 common variants of modest effect size have been reported to be associated with CAD, but many still warrant functional studies. Rare variants impacting the function of at least 10 genes are now well characterized in Mendelian EOCAD. Estimations of minor allele frequencies in multiple ancestries from large genetic databases have allowed us to estimate the prevalence of Mendelian forms of EOCAD. In fact, the prevalence of Mendelian mutations varies markedly between ancestries, ranging from 1 : 289 to 1 : 153 for familial hypercholesterolemia. Mendelian forms of EOCAD support three major biological pathways, including lipid metabolism, vascular wall integrity and function, and thrombosis. Furthermore, combining common variants of modest effect into polygenic risk scores (PRS) has shown to be effective at identifying individuals at high risk of CAD. SUMMARY: Mendelian forms of EOCAD highlight the importance of lipid metabolism, yet prevalence in many non-European populations remains to be clarified. Polygenic EOCAD affects more individuals and, in many cases, confers a higher risk of EOCAD than rare Mendelian mutations. Thus, sequencing of target genes and the derivation of PRSs can be used to identify high-risk patients, leading to more personalized therapeutic approaches.