O51 EXPLORING GENETIC BASIS OF RESISTANT HYPERTENSION IN EUROPEAN AND AFRICAN POPULATIONS

Background: Approximately 15% of hypertensive (HTN) patients experience resistant hypertension (RHTN) despite the use of ≥ 3 antihypertensive agents (diuretic and blockers of calcium channels and the renin-angiotensin system) at maximum tolerated doses. Intriguingly, genetic variation and alterations in gene content may contribute to RHTN developing. Aim: To comprehend the genetic determinants of RHTN across diverse ethnicities, this study has compared the gene content and presence of single nucleotide variants (SNVs) in RHTN versus controlled-HTN and normotensive participants within European (EU) and South African (SA) populations. Methods: Blood-isolated DNA was collected from 6 participants from EU and 15 from SA. Patients were categorized into 3 groups: RHTN (SA; n=5 and EU; n=6), controlled-HTN (n=5), and normotensive (n=5). DNA was used for Whole Exome Sequencing (WES) analysis. Library preparation and exome capture were done using the MGIEasy Universal DNA library prep and exome capture v5 probe set. Mapping was done using GATK, and the variant calling and annotation were performed using with the SIFT tool and R software. Results: PCA analysis and minimum spanning network showed significant genetic diversity between EU and SA populations. WES identified 16 common genes, with 207 and 220 genes associated to RHTN in EU and SA, respectively. These genes were involved in cardiac electrical conduction (K+/Ca++ channels) and lipid storage (HDL deficiency). In addition, SNV within pharmacogenes in SA (CYP2D6, CYP3A5, APOE) and EU (ADD1) cohorts alongside genes linked to disease susceptibility (RyR1 and PPP1CA) were also identified. RyR1 and PPP1CA are both implicated in HTN development through their roles in calcium signaling and vascular smooth muscle cell function. Noteworthy, two SNVs, rs121918006 and rs61732908, within RyR1 were previously linked to HTN. Conclusions: The large genetic differences observed between EU and SA subjects highlight the diverse genetic landscape surrounding RHTN. Notably, specific genes and their related SNV that associated to cardiac calcium channels and lipid storage could show potential targets for personalized therapeutic intervention. Scientific Session 15: Exploring Novel Therapeutic Approaches to Kidney Disease