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Contributor score: 25
Comments ...
claptain
Nvm, this question played me. I realize that E is the only possible choice. Both A and B would be 25% chances, not 50% chances, and you cannot assume whether she is or is not a carrier without genetic analysis (choices C and D). That leaves only E.
+6
beansbeansbeans
Wait I agree with your first comment, can you explain what made you change your mind and understand this?
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yerpderp
They are referring to x inactivation in the daughter which would mean she could be a carrier but we cant tell.
+1
cbreland
so her mom is a carrier because she doesn't have complete symptoms like the brother and uncle?? I guess I thought it was all of nothing with duchenne
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cbreland
Damn, her mom is 50. Duchenne patients don't live that long... nvm dumb on my part, should have made the connection
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j44n
her mom cant have the full blown disease because its an XLR disease. I think we had to narrow this down by process of elimination
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Subcomments ...
claptain
Nvm, this question played me. I realize that E is the only possible choice. Both A and B would be 25% chances, not 50% chances, and you cannot assume whether she is or is not a carrier without genetic analysis (choices C and D). That leaves only E.
+6
beansbeansbeans
Wait I agree with your first comment, can you explain what made you change your mind and understand this?
+
yerpderp
They are referring to x inactivation in the daughter which would mean she could be a carrier but we cant tell.
+1
cbreland
so her mom is a carrier because she doesn't have complete symptoms like the brother and uncle?? I guess I thought it was all of nothing with duchenne
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cbreland
Damn, her mom is 50. Duchenne patients don't live that long... nvm dumb on my part, should have made the connection
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j44n
her mom cant have the full blown disease because its an XLR disease. I think we had to narrow this down by process of elimination
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claptain
Just to add to this, HPV can also inactivate Rb via E7 viral protein.
+3
mamorumyheart
E6: p53
E7: RB
(from FA: 6 before 7, p before R)
+3
claptain
HCTZ and acetazolamide would also deplete potassium, they are just not as strong of diuretics. To be potassium-sparing, it has to have effect at the collecting ducts. Any diuretic that works before the collecting ducts will increase the concentration of sodium going to the collecting ducts and stimulate sodium/potassium exchange at the collecting ducts, potentially leading to decreases in potassium
+4
usmleuser007
would require a a large sample size to see if there is a true difference
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claptain
This question is bogus. CI does not always increase with decreased sample size or vice versa. Four readings with small variation would give a narrower CI than 10 readings with greater variation. The only thing you can be certain about by adding more samples is that the CI will most likely change, but which direction is uncertain.
+9
bartolomoose
Recall the formula for 95%ci
Mean +/- 1.96* (SD/sqrt(samplesize))
+1
the_enigma28
@claptain The point you made is relevant in studies involving random data. But in case of this question, the data being collected is in fact the diastolic BP. We take several readings of BP to rule out white-coat hypertension and have as accurate reading as possible. In this case, taking more readings will actually narrow down the confidence interval. The readings here represent physiological parameter, which wouldn't vary veryyyy widely in an individual.
+1
lowyield
@claptain i was thinking the same thing but ended up choosing the increased because alot of NBME seems to reward the more simplistic answer than the overthinking answer
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I don't understand this question. They equate carrier-status to mean affected by the allele. We know her mother is a carrier because she has elevated CK. That means the patient has a 50% chance to be a carrier since she's female. Random X-inactivation doesn't matter when talking about carrier status because both alleles have a chance to get passed on. Random X inactivation is only important for determining whether she will develop symptoms.
I guess this is why the question was thrown out? Unless I'm missing something.