Two genes BRCA1 and BRCA2 are linked to hereditary breast

Question

Two genes BRCA1 and BRCA2 are linked to hereditary breast cancer. Therefore in order to decrease the annual number of mammogram tests administered across a population and to more accurately assess a woman's individual risk of breast cancer, all women should be tested for these genes.

Which of the following is the assumption?

A. Some women who are tested for the two genes will subsequently undergo mammograms on a less frequent basis than they used to.
B. The majority of breast cancer patients have no family history of the disease.
C. Researchers may have identified a third breast cancer gene that is linked with hereditary breast cancer.
D. Women who have these genes have an 90% chance of getting breast cancer while women who don't have these genes have only a 20% chance of getting breast cancer.
E. The presence of BRCA1 and BRCA 2 can explain upto to 50% of hereditary cases

OA l8r

IanStewart · Accepted Answer

I'm not sure why D is so popular in the above posts. I imagine the people posting above were answering the question "which of the following, if true, would strengthen the argument" and not "which of the following is an assumption in the argument". Those are very different questions.

This is a kind of 'policy proposal' question, where we have a recommended course of action intended to achieve a certain goal. The conclusion here is that "all women should be tested for these genes", and one of the goals is to 'decrease the annual number of mammogram tests'. The assumption must be that testing for these genes will lead to fewer mammogram tests, which is what A says.

D cannot possibly be the assumption here. For one thing, the data given is too precise. You would never need to assume that precisely *90%* of women with these genes get breast cancer for the conclusion to be valid; even if that percentage were relevant to the question (which it isn't) there's no reason we need to assume the percentage is equal to 90.

amit2k9 · Answer

D is clean here.

D is more of a strengthening choice too explaining the fact that the number of tests will reduce and the accuracy will increase too.

vivesomnium · Answer

A. Some women who are tested for the two genes will subsequently undergo mammograms on a less frequent basis than they used to -this is partial- and weak. it says some women(not most), and it doesnt talk at all of "more accurately assess a woman's individual risk of breast cancer"
B. The majority of breast cancer patients have no family history of the disease.: This cant be an assumption as it will be weakening to the argument, so it cant be something that the argument depends on.
C. Researchers may have identified a third breast cancer gene that is linked with hereditary breast cancer.: Similar to B, this will actually be weakening to the argument
D. Women who have these genes have an 90% chance of getting breast cancer while women who don't have these genes have only a 20% chance of getting breast cancer. this brings into picture that even if there are reasons beyond the presence of these two genes, the instances are rarer. Therefore, it is a correct assumption.
E. The presence of BRCA1 and BRCA 2 can explain upto to 50% of hereditary cases upto 50%- very weak. as there would still be a lot of cases in which there wouldnt be this gene and the risk would still be there, which means testing for these genes cant accurately help assess the risk of breast cancer in more than 50% of the cases! incorrect.

Answer should be D

joshnsit · Answer

How is D talking about reduction in number of tests?

joshnsit · Answer

Guys Can I atleast know the conclusion here which needs to be supported and defended here? I am now facing a big problem in demarcating in the conclusion itself here :oops:

Carcass · Answer

i find it in about 1.10 the time to read all the question. So, I think in somehow you overcalculate sometimes and I see this through your post.

Think in this way. We have the passage, and you must tackle the Cr (or almost this kind) so: Two genes BRCA1 and BRCA2 are linked to hereditary breast cancer - PREMISE Therefore in order to decrease the annual number of mammogram tests administered across a population and to more accurately assess a woman's individual risk of breast cancer, all women should be tested for these genes - CONCLUSION But in this latter trying to go to the core of the question and eliminate the verbose part that put you in the wrong way or confuse you. In this case you read only the part in bold After this I do in that way: I read A and if cuold be good i hold it, if does not have nothing or add unuseful information...delete. without doubt. I read B and so on.......in this way you have for sure 2 or at most 3 choice and so you can pick between these. NOW: in this case thanks to the premise that says us: who have this 2 kind of genes could have breast cancer --------> all women should be tested for these genes. Here I see more clear that the only bridge that binds the two things is ONLY who has this markers - in medical meaning - has more risk to became a sick person, so make a mammogram e bla bla bla.......... To sum up, who has this genes should do the mammogram because have an high risk to fall ill.......who not could help to reduce the cost binds with the use and/or abuse of mammogram and weigh on health sector indeed the correct answer is D

subhashghosh · Answer

I think the correct answer is A, becuase it is the bare minimum truth required to validate the conclusion. D should flash across as a red herring because nowhere in the stimulus anything related to percentage is mentioned.

joshnsit · Answer

Thanks for this discussion guys. Ian made it much clearer than the actual OE I have.
The OA is A.

amit2k9 · Answer

Oh man !! Yes D is strengthening answer choice,as I mentioned this in my earlier post too.
yes A is indeed the assumption here,thereby confirming that at least some woman will have lesser frequency of tests taken.

A is indeed the answer here.

Carcass · Answer

mmmmmm I was quite sure about D.

isst80 · Answer

A. Keeping the scope of the conclusion in mind helped me with this one. Since the goal is to reduce mammogram tests the correct answer choice must relate to tests in some way.

kinghyts · Answer

D) doesn't seem to be the assumption. Any choice that gives fact and figures are usually incorrect as the correct choice in an assumption question, because we can negate the choice easily or the facts doesn't have to hold true for the conclusion to be correct.

Let us try to negate the answer choice D), which says "Women who have these genes have an 90% chance of getting breast cancer while women who don't have these genes have only a 20% chance of getting breast cancer."

Negated choice : Women who have these genes doesn't have 90% chance of getting breast cancer while women who don't have these genes doesn't have only a 20% chance of getting breast cancer.

The negated choice doesn't destroy the conclusion, since let say "women with such genes might have 75% chance of getting breast cancer" and that could be sufficient for all women to go through the test.

Experts please help

VSabc · Answer

Two genes BRCA1 and BRCA2 are linked to hereditary breast cancer.  (premise) Therefore in order to decrease the annual number of mammogram tests administered across a population and to more accurately assess a woman's individual risk of breast cancer,  all women should be tested for these genes.  (conclusion)
We have to pick the answer which lets us conclude from the premise. Conclusion is to reduce woman's risk of breast cancer and we know the two genes are linked to  hereditary  breast cancer.
A. Seems pretty good, let's keep it for the time being
B. If this was true, checking for the two genes wouldn't help at all. Wrong choice
C. So what? Does it add any value in our question stem? Probably not, rejected
D. Most contentious so far from posts above. Question is asking about an assumption which should be pretty concrete. Can the assumption really be based upon precise nos. It is saying as if 'I'll climb Mount Everest only if it is 8933.2m and I won't if it is 8933.5m" Doesn't seem likely that the conclusion (women should undergo the test) shall be considered only if 90% stat is met. Rejected..
E. Again, too precise % figures. Rejected

Now, let's consider A as an answer choice. Objective is to lower the no. of mammograms and assess the risk more accurately and hence reduce it. If the women are tested for the two genes, they need not undergo the mammogram but still can be diagnosed more accurately. Hence, there will be fewer mammograms for women who have undergone the test for 2 genes. Hence, the answer choice A. Hope this helps.

aniteshgmat1101 · Answer

Answer should be A.
Objective is to reduce the number of mamo test by assessing women for the 2 genes. So, the assumption is that test will help to do so.

thangvietname · Answer

thank you expert,
I feel that when the argument is a proposal, the assumption is the argument itself. this case make the argumet simple and weid

is my thinking correct? expert. knowing this case help us overcome weid thinking is proposal passage

Guilio · Answer

I also picked D first and was 100% sure in my answer. I understand why A is better, however one thing I don't understand is why everybody keeps mentioning that the objective here is solely to reduce the number of memo tests? The way I see it, the argument has two goals: a) do decrease the number of memo tests AND to more accurately asses a woman's individual risk of breast cancer. This is what probably led most of us to wrong conclusion by crossing off A and picking D instead as D essentially talks about these risks.

D really would be a typical "strengthen the argument" answer and I understand now that it doesn't work in this context. I was more wondering why you guys refute the importance of the second objection. Clearly this helped you spot the flaw in answer D - "I don't care about the risks, so I focus on reducing the number of memo tests." If you worked through the problem this way, sure you didn't bother considering D in the first place.

So my question in short: why did you drop the objection 2 from your reasoning?

saikiransomala · Answer

Hi,

Answer should be A.

We are looking for a situation where the gene identification can decrease the number of tests. 
Hence the choice A if negated breaks the conclusion.

Regards
Sai Kiran

khoathanglong · Answer

Though A seems to be right, I still doubt it.
Conclusion: to reduce the number of tests -> all women should be tested
in A: some women is tested -> Reduce number of tests
How can sufficient and necessary condition apply in this case? 
Some experts please help!

OptimusPrepJanielle · Answer

Premise: BRCA1 and BRCA2 are linked to hereditary breast cancer. 
Conclusion: To reduce mammogram tests and accurately identify risk, women should be tested for these genes.

On looking at the options, only A and D remain. 
Option A gives us a reason to assume that if the women are tested for these genes, they will go for the mammogram test on a less frequent basis and thus support our conclusion. Hence the correct option.

Option D on the other hand is a trap option and does not tell us anything about our conclusion of reduction of tests. 
Moreover any options with such precise percentages or numbers should be dealt with carefully in an assumption question as they are often not the correct option.

Correct Option: A

Two genes BRCA1 and BRCA2 are linked to hereditary breast

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

GMAT Critical Reasoning (CR) Questions

Two genes BRCA1 and BRCA2 are linked to hereditary breast

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia