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High Yield Question #12

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genetics-
5K views 6 replies 5 participants last post by  dr mumble 
#1 ·
A couple has three girls, the last of whom is affected with cystic fibrosis. The first-born daughter marries her first cousin-that is, the son of her mother's sister-and they have a son with cystic fibrosis. The father has a female cousin with cystic fibrosis on his mother's side. Which of the following pedigree diagrams best represents this family history?

Font Pattern Handwriting Circle Design

click image to enlarge

A. Diagram A
B. Diagram B
C. Diagram C
D. Diagram D
E. Diagram E
F. Diagram F
G. Diagram G
H. Diagram H
 
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#4 ·
F) Diagram F

F matches best!
He is right.

Correct ans is F) Diagram F

It is important that the pedigree be an accurate reflection of the family history and that information not be recorded unless specifically mentioned. Pedigree B in the figure omits the double line needed to indicate consanguinity, and pedigree C assumes that the father's affected cousin is the offspring of his uncle rather than being unspecified. Pedigree F correctly illustrates the birth order (third) of the affected female (indicated by arrow) and the consanguinity (double line) represented by the first-cousin marriage.

Highly tested pedigrees are...

Autosomal recessive


X-linked recessive


Mitochondrial


Know them well.
 
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