Based on the World Health Organization’s (WHO) latest recommendation, the current case definitions of G6PD deficiency are as follows: males and females with <30% of normal enzyme activity are G6PD deficient, heterozygous females with enzyme activity of 30%–80% are G6PD intermediate, and males with >30% and females with >80% activity levels are G6PD normal (World Health Organization, 2016). The gene discussed is G6PD; the disease is hyperinsulinemic hypoglycemia, familial, 4.