Question

Glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as an X-linked recessive allele in humans. A woman whose father suffered from G6PD marries a man who has the disease. What proportion of their sons would have the disease?

Answer 1

Answer:

Half (1/2) of the sons or 50 %

Explanation:

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme deficiency in humans. It is inherited as an X-linked recessive disorder. Let’s assume the gene “g” located on the X chromosome causes the (G6PD) deficiency disorder which will inherited by daughters from the affected father.  One allele of the said gene on the X chromosome in female acts as carrier and the presence of the allele “g” on both the X chromosomes will cause G6PD disorder in female.  

In the given question, the female whose father was affected with G6PD disorder is married to an affected male.

The genotype of the female would be "XgX". The genotype of the disordered male would be "XgY".

Therefore, marriage between carrier female and affected male would have 50% affected sons and 50% normal.