The rs1050828 A allele is a diagnostic SNP of the type A- G6PD deficiency genotype. While the G allele (rs1050828(G;G)) is associated with 'normal' levels of glucose-6-phosphate dehydrogenase, the A allele is associated with a reduction of G6PD production. Because rs1050828 is located on the X chromosome, only females can be heterozygous for both the A and G allele. Furthermore, due to the process of X chromosome lyonization, the severity of G6PD deficiency will vary across females. G6PD type A- is predominantly found in individuals with African ancestry while the G allele is found in other ethnic groups. The rs1050828 A allele is also associated with malarial resistance.