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Old 06-29-2012
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DNA Tumor Suppressor Gene; One or Two Mutations!

Question:

You are examining a healthy 23-year-old woman with a family history of multiple cancers (mother had breast, grandmother/sister had ovarian). What do you expect to find on gene analysis of this woman?

A) 1 mutation of tumor suppressor gene
B) 2 mutations of tumor suppressor gene




So this is a classic Li-fraumeni case but I am a bit confused with the answer choices. In LF there is a germline mutation of 1 of the p53 genes, and later on in life the patient acquires the other mutation somatically. I want to say B, but do you have the assume that all LF patients will acquire that second mutation in p53 even if they don't have cancer at the very moment?
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Old 06-29-2012
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Hey i think this could be a BRCA 1 mutation too, not necessarily li-fraumeni right??
Either way they r both tumor suppressor gene mutations.
I would go with A. mutation of 1 tumor suppressor gene because it says the patient is healthy so she probably has not acquired the 2nd hit yet.
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Old 06-29-2012
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yea i guess it could be BRCA-1 as well. But lets just suppose its LF.
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A) 1 mutation of tumor suppressor gene 2 hit theory
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Old 07-19-2012
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Old 07-19-2012
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p53 is a tumor suppressor gene . "2-hit theory" for this work. Complementary allele must be deleted/mutated before cancer develops.
On the other hand, oncogene require only one hit.
Answer will be B.
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Old 07-19-2012
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^answer is A, dood
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Old 07-19-2012
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Quote:
Originally Posted by No_BS View Post
Question:

You are examining a healthy 23-year-old woman with a family history of multiple cancers (mother had breast, grandmother/sister had ovarian). What do you expect to find on gene analysis of this woman?

A) 1 mutation of tumor suppressor gene
B) 2 mutations of tumor suppressor gene

So this is a classic Li-fraumeni case but I am a bit confused with the answer choices. In LF there is a germline mutation of 1 of the p53 genes, and later on in life the patient acquires the other mutation somatically. I want to say B, but do you have the assume that all LF patients will acquire that second mutation in p53 even if they don't have cancer at the very moment?
definitely AAaaaaaaaaa
once the 2nd allele is mutated,she will be Unhealthy
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Old 07-19-2012
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Quote:
Originally Posted by eveli55 View Post
p53 is a tumor suppressor gene . "2-hit theory" for this work. Complementary allele must be deleted/mutated before cancer develops.
On the other hand, oncogene require only one hit.
Answer will be B.
answer is A, yep
I misread whole Q!
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