Question

Which of the following describes what happens in a family where one of the parents has a mitochondrial disease?

(A) All of the children of an affected mother will inherit the disease.
(B) All of the children of an affected father will inherit the disease.
(C) Only males will be affected if the mother has the disease.
(D) Only females will be affected if the father has the disease.

Answer 1

In families with mitochondrial diseases, all of the children of an affected mother will inherit the disease because mitochondria, and therefore mitochondrial DNA, are inherited maternally.

Step-by-step explanation:

The question concerns the inheritance pattern of mitochondrial diseases, which are genetic disorders affecting cellular metabolism. Mitochondria have their own DNA, separate from nuclear DNA, and because they are inherited maternally, the pattern of inheritance for mitochondrial diseases is also maternal. This means that children inherit these diseases specifically from their mother, not their father.

Therefore, the correct answer to the question is (A) All of the children of an affected mother will inherit the disease. This is different from X-linked recessive diseases, where males are more often affected and females can be carriers. Mitochondrial diseases can result from mutations in the mitochondrial DNA leading to a range of symptoms, such as muscle weakness, lack of coordination, and loss of vision and hearing. These disorders are diagnosed and treated by specialists such as a Mitochondrial Disease Physician.