GRK4 and obesity due to melanocortin 4 receptor deficiency: As well, 2-locus of GRK4 A142V and CYP11β-2 C344T was 77.8% predictive of low-renin hypertension in Japanese.[14] In terms of the GRK4 gene, the A486V mutant was a risk factor of obesity, whereas the A142V mutant suppressed the obesity risk.