Question

A 23 year old female presents with bilateral loss of central vision. You obtain a detailed family history and produced the associated pedigree. Which of the following transmission patterns is most consistent with this patient's family history?
a. Autosomal dominant
b. Autosomal recessive
c. X-linked dominant
d. X-linked recessive
e. Mitochondrial

Answer 1

Answer:

e. Mitochondrial

Explanation:

• This is a case of mitochondrial heredity so correct answer is e. Mitochondrial
• In this case, the mother transfers her mitochondria to her children. So the child is affected. The male does not pass this trait on to his children.
• We can see from the lineage that the mother has defective mitochondria so all their children will have defective mitochondria. One of his sons has mitochondrial, but is unable to pass it on to the next generation.