Which of the following is a potential challenge when diagnosing mitochondrial diseases using family history alone?
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Correct answer: Variable heteroplasmy and penetrance can mask maternal transmission
Because heteroplasmy can vary between individuals and tissues, and disease expression depends on mutant load, an affected mother might appear asymptomatic — obscuring maternal transmission when relying solely on pedigree.
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More Mitochondrial inheritance questions
- Which of the following statements about nuclear-encoded mitochondrial proteins and their inheritance is correct?
- Which mitochondrial feature makes mtDNA a useful tool for tracing human maternal ancestry over many generations?
- Which of the following would be strong evidence for a nuclear (rather than mitochondrial) cause of a suspected mitochondrial disease?
- Why might a heteroplasmic mother have both affected and unaffected children when carrying a deleterious mtDNA mutation?
- Which inheritance pattern best describes transmission of mutations in mitochondrial DNA (mtDNA) in humans?
- In a family pedigree for a mitochondrial disease, which of the following patterns is expected if the disease is due to an mtDNA mutation?