CYP3A4 and hypertensive disorder: Several studies have identified SNPs in genes that affect the pharmacokinetics of drugs used in the treatment of hypertension which include ABCB1, CES1, CYP2C9, CYP2D6, CYP3A4, CYP3A5, and SLCO1B1. CYP2D6 nonfunctional and reduced function variants have been profiled and identified among Africans [48, 116].