Alpha globin gene copy number and incident ischemic stroke risk among Black Americans.

Although a reduction in copy number is expected to increase endothelial nitric oxide signaling in the human vascular endothelium, copy number was not associated with incident ischemic stroke in this large longitudinal cohort of Black Americans. This finding is consistent with a prior study demonstrating no association between copy number and hypertension but differs from a study demonstrating an association with chronic and end-stage kidney disease in which gene deletions are protective. Together, these population studies suggest that the physiological roles of alpha globin may differ between the renal and cerebral vascular beds.