Prep for USMLEPrep for USMLE
         Forum      |     Resources New Posts   |   Register   |   Login





 gardners  



Post Reply  
  • 0/5
  • 1
  • 2
  • 3
  • 4
  • 5


Author9 Posts
  #1

Family with father ,grandfather and grandmother suffering from gardner's syndrome.father has 4 children.what are the chances that atleast one child has inherited the gardner's syndrome allele?

A.1/4
B.1/2
C.3/4
D.13/16
E.15/16





  #2

U had posted a similar q (wardenburg's). We lesser mortals got stumped. Could u tell us watz the answer for both the Q?


  #3

for wardenbugs ur right. 1/8
1/2x1/2x1/2
try this. i will post the ans later..


  #4

here it is E



  #5

Econfused


  #6

Can anyone exlain the answer E?



  #7

gardener is autosomal dominant.

1 st genereration risk is 50%
2 nd gen risk is 25% (1/4)

total probability of all 4 children affected is 1/4 *1/4*1/4*1/4 =1/16

probability of atleast one child affected=1-1/16=15/16


  #8

hw could the risk in first gen be 50 % bs both grandfather and gr mother affected, so chance must be 75%confused


  #9

Ans E?

1st gen

Aa * Aa

AA Aa Aa aa

So chance that father has diseased allele is 3/4

2nd gen

Aa * aa

Aa Aa aa aa

so risk is 50 % ie 1/2

chance for all 4 to be affected is 1/2 * 1/2 * 1/2 * 1/2 = 1/16

Risk of atleast 1 having disease allele = 1-1/16= 15/16

grin






Bookmark and Share



This thread is closed, so you cannot post a reply.



Login or Register to post messages








show Similar forum topics

show Related resources









Advertise | Support | Premium | Contact