G6PD and G6PD deficiency: Although G6PD deficiency may be diagnosed via spectrophotometry to assess G6PD enzyme activity, fluorescent spot testing to detect nicotinamide adenine dinucleotide phosphate (NADPH) produced by G6PD, or genotyping of common variants in certain populations, such as p.Val68Met in individuals of African ancestry, people with G6PD deficiency typically remain unidentified unless they experience rare hemolytic crises.2