Question

The pedigree below tracks Duchenne Muscular Dystrophy (DMD) through several generations.
If individuals I-1 and I-2 had another son, what is the chance that he would have DMD?

• A. $0\%$
• B. $25\%$
• C. $50\%$
• D. $100\%$

Answer 1

The correct option is D $100\%$

As from pedigree DMD is an X linked recessive disease which will be seen in males mainly. As I-2 is affected she can pass only recessive gene and all sons will be affected and daughters will be carrier.