As shown in Table 4, RhD-negative patients had a lower age at diagnosis (p=0.035) with a mean age of 48 years compared with a mean age of 55.8 years in patients with positive RhD, and a lower rate of hypertension (6.7% in RhD-negative vs 35.2% in RhD-positive, p=0.035). This evidence concerns the gene RHD and hypertensive disorder.