Third, HbA1c is reported to have a lower sensitivity at cut-points of 5.7–6.4% and is associated with greater diagnostic inaccuracy in the presence of certain medical conditions that increase red blood cell turnover (e.g., sickle cell disease, pregnancy, erythropoietin therapy)1 and are not reported in NHANES. The gene discussed is EPO; the disease is sickle cell disease.