I gto sith eno wn,ogr ubt abdes on hte TIT eppvrscitee erhsot im,ntondee aymeb the ni" itreh mrapryi sani"lays rpta fo teh utoineqs is a tip off. eTyd'h tsrat thwi ciinundgl temh in the raogiiln pgsoru nda hetn od dnaiiatodl nsyasail to yrt dan tseae out the paim?tc IDK
Am I crazy, or does the question stem imply that this was inherited paternally?
This question might be tricky because the mutation of interest here is inherited from the dad side (paternal) but affects the mitochondria.
That is, the mutation is not a mutation of the mitochondrial DNA.
In their explanation, the NBME says, “
Mitochondrial diseases are strictly inherited through the mother” but that is incorrect; it would be more correct for them to have said: Mitochondrial DNA mutations are strictly inherited through the mother.
In other words, the stem does not describe a "
mitochondrial disease" in the way the NBME defines it.
Yes, mitochondria are affected but the mutation is in nuclear DNA that govern the maintenance of "healthy mitochondria". The mutation affects the function and operation of mitochondria but the mutation itself is in the nuclear DNA (which control something about the "quality" of mitochondria but what exactly is not yet understood).
This explains why dad and dad's brother show the same “proximal muscle weakness of the lower extremities”.