USMLE Step 1 Quiz
20 questions · no time limit
0:00
BIOCHEMISTRY
Question 1 of 20
No time limit
Current
Answered
Flagged
Not seen
PASSAGE
An 8-year-old boy presents with progressive external ophthalmoplegia, pigmentary retinopathy, and a heart block detected on ECG. His parents are healthy and unrelated. The patient's condition appeared sporadically, with no other family members affected. Genetic analysis reveals a large deletion in his mitochondrial DNA, which is not present in his mother's blood cells.
This patient's disorder is best described as having which of the following inheritance patterns?
YOUR PROGRESS
20
QUESTIONS
Ready when you are
Answer in any order. Your progress shows here as you go.
QUESTIONS
KEYBOARD
Pick an answer ABCD
Next question ↵→
Previous ←
Flag for review F
Answers save as you go · flagged questions come back at the end