Background: Cardiovascular diseases (CVDs) are the leading cause of non-communicable disease deaths globally, with hypertension being a major risk factor contributing to CVDs. Blood pressure is a heritable trait, with relatively few genetic studies having been performed in Africans. This study aimed to identify genetic variants associated with variance in systolic (SBP) and diastolic (DBP) blood pressure in black South Africans.
Methods: Genotyping was performed using the Metabochip in a subset of participants (mixed sex; median age 17.9) and their adult female caregivers (median age 41.0) from the Birth to Twenty cohort (n = 1947). Data were analysed as a merged dataset (all participants and caregivers together) in GEMMA (v0.94.1) using univariate linear mixed models, incorporating a centered relatedness matrix to account for the relatedness between individuals and with adjustments for age, sex, BMI and principal components of the genotype information.
Results: Association analysis identified regions of interest in the NOS1AP (DBP: rs112468105 - p = 7.18 × 10-5 and SBP: rs4657181 - p = 4.04 × 10-5), MYRF (SBP: rs11230796 - p = 2.16 × 10-7, rs400075 - p = 2.88 × 10-7) and POC1B (SBP: rs770373 - p = 7.05 × 10-5, rs770374 - p = 9.05 × 10-5) genes and some intergenic regions (DACH1|LOC440145 (DBP: rs17240498 - p = 4.91 × 10-6 and SBP: rs17240498 - p = 2.10 × 10-5) and INTS10|LPL (SBP: rs55830938 - p = 1.30 × 10-5, rs73599609 - p = 5.78 × 10-5, rs73667448 - p = 6.86 × 10-5)).
Conclusions: The study provided further insight into the contribution of genetic variants to blood pressure in black South Africans. Future functional and replication studies in larger samples are required to confirm the role of the identified loci in blood pressure regulation and whether or not these variants are African-specific.
Keywords: Birth to Twenty; Metabochip; black South Africans; blood pressure; genetics.