I believe my chosen answer is correct, but I\'m not entirely positive. Any help is appreciated. The enzyme glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as a recessive gene on the X chromosome in humans. Below is a pedigree of a family affected by G6PD. X- represents a mutant X chromosome. What is I-1\'s genotype? XX. XX- X-X- could be A or B Solution G6PD is recessive traits disease and so in I-2 the Male would be having diseased X chromosome recessive traits now for being disease in II a male must have a single disease X trait for that if female is homozygous for non disease trait of heterzygous for disease trait in both condition in I is possible. So condition A and B both is correct.