Functional and Biochemical Analysis of Glucose-6-Phosphate Dehydrogenase (G6PD) Variants: Elucidating the Molecular Basis of G6PD Deficiency

G6PD deficiency is the most common enzymopathy, leading to alterations in the first step of the pentose phosphate pathway, which interferes with the protection of the erythrocyte against oxidative stress and causes a wide range of clinical symptoms of which hemolysis is one of the most severe. The G6PD deficiency causes several abnormalities that range from asymptomatic individuals to more severe manifestations that can lead to death. Nowadays, only 9.2% of all recognized variants have been related to clinical manifestations. It is important to understand the molecular basis of G6PD deficiency to understand how gene mutations can impact structure, stability, and enzymatic function. In this work, we reviewed and compared the functional and structural data generated through the characterization of 20 G6PD variants using different approaches. These studies showed that severe clinical manifestations of G6PD deficiency were related to mutations that affected the catalytic and structural nicotinamide adenine dinucleotide phosphate (NADPH) binding sites, and suggests that the misfolding or instability of the 3D structure of the protein could compromise the half-life of the protein in the erythrocyte and its activity.