Glucose-6-phosphate dehydrogenase deficiency is an X-linked disorder occurring in approximately 10% of Africans and peri-Mediterranean populations.

Glucose-6-phosphate dehydrogenase deficiency is an X-linked disorder occurring in approximately 10% of Africans and peri-Mediterranean populations.

• A. Autosomal recessive
• B. X-linked
• C. Autosomal dominant
• D. Mitochondrial inheritance

Answer: (B)

G6PD deficiency is inherited through the X chromosome, so it follows an X-linked pattern. Because males have only one X, a single mutant G6PD allele will produce the deficiency, making affected individuals more commonly male. Females usually need two copies to be affected and are often carriers, explaining why many people, especially females, are asymptomatic carriers. The notable frequency in African and peri-Mediterranean populations reflects historical malaria pressure, which increased the allele’s frequency because carriers have some protective advantage. This combination of gene location and sex-specific expression is why the correct description is X-linked inheritance, rather than autosomal or mitochondrial patterns.

G6PD deficiency is inherited through the X chromosome, so it follows an X-linked pattern. Because males have only one X, a single mutant G6PD allele will produce the deficiency, making affected individuals more commonly male. Females usually need two copies to be affected and are often carriers, explaining why many people, especially females, are asymptomatic carriers. The notable frequency in African and peri-Mediterranean populations reflects historical malaria pressure, which increased the allele’s frequency because carriers have some protective advantage. This combination of gene location and sex-specific expression is why the correct description is X-linked inheritance, rather than autosomal or mitochondrial patterns.