Validation of Diagnostics to Identify Glucose-6-phosphate Dehydrogenase Activity in the US

This is a cross-sectional diagnostic accuracy study with up to 250 participants with a goal of obtaining 20 deficient and 20 intermediate samples. The clinic will recruit and consent study participants. Clinic staff will draw 3 whole blood samples and obtain finger stick capillary blood. G6PD activity is reported in terms of grams of hemoglobin (Hb), hence the hemoglobin concentration must be measured. Clinic staff will perform the investigational Standard Diagnostics (SD) Biosensor point-of-care (POC) test for glucose-6-phosphate dehydrogenase (G6PD) deficiency and a HemoCue® hemoglobin test on finger stick capillary blood and on the venous blood samples. Another venous blood sample will be sent to a clinical laboratory improvement amendments (CLIA)-certified laboratory for reference testing by the gold standard assays: * G6PD measurement by spectrophotometry using the Pointe Scientific G6PD reference assay * hemoglobin measurement by a hematology analyzer Individuals identified as G6PD deficient with the reference test will be notified of their results by the clinic and referred to their physician for follow-up.