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  #1  
Old 11-18-2012
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Genetics Genetics question

A 25 year old woman presents to your clinic with carcinoma of her right breast. Her sister was also diagnosed with breast carcinoma at age of 28. Her father suffered from myxofibrosarcoma and her younger brother died at age 5 with medulloblastoma. She has a nephew aged 8, who suffers from rhabdomyosarcoma.

This pedigree illustrates

a. genetic heterogenicity
b. incomplete penetrance
c. multifactorial inheritance
d. variable expressivity
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  #2  
Old 11-18-2012
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C. Mutifactorial inheritence ?????
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Old 11-18-2012
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well, its just that non of the options make perfect sense. The family is packed with a a bunch of malignancies so I think one of the familial cancer syndromes like Li Freumani Syndrome (p53 mutation) is involved. Therefore I don't think it is multifactorial. But I am confused between a. genetic heterogenicity and b. variable expressivity.
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Old 11-18-2012
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Quote:
Originally Posted by wertheworld11 View Post
well, its just that non of the options make perfect sense. The family is packed with a a bunch of malignancies so I think one of the familial cancer syndromes like Li Freumani Syndrome (p53 mutation) is involved. Therefore I don't think it is multifactorial. But I am confused between a. genetic heterogenicity and b. variable expressivity.
To be honest I thought the same...and got confused thats why I was not sure and put a question mark at the end of my answer.

But I doubt a and b either.

I could be wrong.
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Old 11-18-2012
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Quote:
Originally Posted by wertheworld11 View Post
well, its just that non of the options make perfect sense. The family is packed with a a bunch of malignancies so I think one of the familial cancer syndromes like Li Freumani Syndrome (p53 mutation) is involved. Therefore I don't think it is multifactorial. But I am confused between a. genetic heterogenicity and b. variable expressivity.
I would go for loss of heterozygosity. as you said, p53 li freumeni syndrome should be suspected
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Old 11-18-2012
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Quote:
Originally Posted by wertheworld11 View Post
A 25 year old woman presents to your clinic with carcinoma of her right breast. Her sister was also diagnosied with breast carcinoma at age of 28. Her father suffered from myxofibrosarcoma and her younger brother died at age 5 with medulloblastoma. She has a nephew aged 8, who suffers from rhabdomyosarcoma.

This pedigree illustrates

a.genetic heterogenicity
b. incomplete penetrance
c. multifactorial inheritance
d. variable expressivity
I think B is the best option in given scenario
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Old 11-18-2012
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I think it is A, if there is any correct answer
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Old 11-19-2012
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My answer is D: variable experssion.

I think Genetic and locus heterogenisty are one and same thing. Option A would have been appropriate answer if it was Loss of Heterozygosity.
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Old 11-19-2012
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Quote:
Originally Posted by wertheworld11 View Post
A 25 year old woman presents to your clinic with carcinoma of her right breast. Her sister was also diagnosed with breast carcinoma at age of 28. Her father suffered from myxofibrosarcoma and her younger brother died at age 5 with medulloblastoma. She has a nephew aged 8, who suffers from rhabdomyosarcoma.

This pedigree illustrates

a. genetic heterogenicity
b. incomplete penetrance
c. multifactorial inheritance
d. variable expressivity
I think it would be variable expressivity
As genetic heterogenicity would be something like different alleles causing single disorder.
Whereas this case look like p53 mutation.
Other options are less probable.


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  #10  
Old 11-20-2012
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Can u please post the answer with explanation
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  #11  
Old 12-06-2012
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i actually don't understand the answer.

wouldn't variable expressivity mean different phenotypic types for the same genetic disease?
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