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  #1  
Old 07-04-2011
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Genetics Colon cancer pedigree

Martha is 31 and has come for a routine gynecologic visit. The physician has not seen her before and obtains a family history, which reveals several individuals with colon cancer in her motherís family. Marthaís mother died in an accident at age 38 and was not known to have any health problems. Martha tells the physician she feels fine and, be- cause her two older siblings have not been diagnosed with any health problems, has considered herself unlikely to be at risk for any problems.

Colon cancer pedigree-screen-shot-2011-07-04-10.48.12-pm.png
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The physician would most likely advise Martha that


A. The high frequency of colon cancer suggests that her maternal grandfather (II-1) is a carrier of this recessive trait.
B. Because her mother and uncles were not affected it is unlikely that she will de- velop colon cancer.
C. She should have a colonoscopy at age 50.
D. Her 60-year-old maternal uncle (II-4) should have a colonoscopy.
E. Her mother likely was a carrier for this trait, but her father (III-1) likely was not a carrier, and thus her siblings are unaffected.
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  #2  
Old 07-04-2011
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Default Colon cancer pedigree

i think its E..............
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  #3  
Old 07-04-2011
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its c........
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  #4  
Old 07-04-2011
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I will go with C.
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  #5  
Old 07-04-2011
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Although A seems to be right..But physician should advice MARTHA to have a colonoscopy at 50..So its C..
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  #6  
Old 07-04-2011
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"C. She should have a colonoscopy at age 50. "

Colorectal cancer screening recommendations (patient without risk factors): colonoscopy every 10 years, beginning at age 50...

Do you really think this is the best answer for a patient with risk factors???
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  #7  
Old 07-04-2011
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Default Ans.

I choose D. Familial adenomatous polyposis and HNPCC are autosomal dominant mutation.

Last edited by NGaleas; 07-04-2011 at 08:23 PM.
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I will go with c, cos she has nothing to lose anyway for the screening exam.
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  #9  
Old 07-04-2011
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Quote:
Originally Posted by skido View Post
I will go with c, cos she has nothing to lose anyway for the screening exam.
@skido
You are absolutely right...but if you choose C), Martha would have to wait 20 years for that
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I think is D. Her 60-year-old maternal uncle (II-4) should have a colonoscopy.
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  #11  
Old 07-05-2011
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well...the condition is AD n malignant transformation occurs by 35-40 yrs age so one cnt advice sme1 with history of colon cancer in family to w8 fr tht long ruling out all others my ans is D
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  #12  
Old 07-05-2011
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Correct Answer correct answer

The correct answer is D)

The kindred might show a recessive trait (choice A), but a dominant one is much more likely, placing II-4, the 60-year-old uncle, at 50% risk.
Martha is at risk (choice B); she needs a colonoscopy now and should not wait to have a routine test at age 50 (choice C). Her fatherís status is not relevant to the segregation of an AD trait (choice E). The physician also needs to know what sort of colon cancer was present in family (ie, were polyps prominent?). Given the variability in phenotypic expression of AD traits, it is difficult to predict age of onset of symptoms.
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  #13  
Old 07-05-2011
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I agree

sry im late i was gonna put D coz the C u do it for everyone
and bebix thx for the good questions
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  #14  
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Quote:
Originally Posted by bebix View Post
The correct answer is D)

The kindred might show a recessive trait (choice A), but a dominant one is much more likely, placing II-4, the 60-year-old uncle, at 50% risk.
Martha is at risk (choice B); she needs a colonoscopy now and should not wait to have a routine test at age 50 (choice C). Her fatherís status is not relevant to the segregation of an AD trait (choice E). The physician also needs to know what sort of colon cancer was present in family (ie, were polyps prominent?). Given the variability in phenotypic expression of AD traits, it is difficult to predict age of onset of symptoms.
This one is pretty confusing..i didnt get the concept..
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  #15  
Old 07-12-2011
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Quote:
Originally Posted by bebix View Post
The correct answer is D)

The kindred might show a recessive trait (choice A), but a dominant one is much more likely, placing II-4, the 60-year-old uncle, at 50% risk.
Martha is at risk (choice B); she needs a colonoscopy now and should not wait to have a routine test at age 50 (choice C). Her fatherís status is not relevant to the segregation of an AD trait (choice E). The physician also needs to know what sort of colon cancer was present in family (ie, were polyps prominent?). Given the variability in phenotypic expression of AD traits, it is difficult to predict age of onset of symptoms.
except her maternal grand mom , everyone else had onset of cancer in their 50's , while the typical presentation of a hereditary colon cancer is early 40's .. so hw can we expect this to b familial....i kno its hard to believe these many deaths due to sporadic cases of colon cancer....
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  #16  
Old 07-12-2011
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Quote:
Originally Posted by drnirajmavani View Post
except her maternal grand mom , everyone else had onset of cancer in their 50's , while the typical presentation of a hereditary colon cancer is early 40's .. so hw can we expect this to b familial....i kno its hard to believe these many deaths due to sporadic cases of colon cancer....
Amsterdam Criteria:
Three or more family members with a confirmed diagnosis of colorectal cancer, one of whom is a first degree (parent, child, sibling) relative of the other two
Two successive affected generations
One or more colon cancers diagnosed under age 50 years
Familial adenomatous polyposis (FAP) has been excluded
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  #17  
Old 12-07-2011
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Default NIce...

Quote:
Originally Posted by bebix View Post
Amsterdam Criteria:
Three or more family members with a confirmed diagnosis of colorectal cancer, one of whom is a first degree (parent, child, sibling) relative of the other two
Two successive affected generations
One or more colon cancers diagnosed under age 50 years
Familial adenomatous polyposis (FAP) has been excluded
I got fooled by C...
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  #18  
Old 06-06-2016
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Angry

these pedigrees are so tricky... i was fooled by C too
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