15 Pedigree Flashcards Preview

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Flashcards in 15 Pedigree Deck (8)
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1
Q

What does a diamond in a pedigree mean?

A

unknown

2
Q

What does a number inside a shape on a pedigree mean?

A

Indicates multiples of offspring in large pedigrees

3
Q

What does a Y shaped connector for offspring indicate?

A

twins if identical also has a crossbar

4
Q

What are double horizontal lines in pedigree mean?

A

consanguineous

5
Q

What does a dot in the middle of a symbol mean?

A

X linked Carrier

6
Q

How does consanguinity affect probability of recessive genes?

A

The probability of shared genes being passed increases for every generation of offspring that were from consanguineous mating

7
Q

Give the probability of sharing a gene from siblings to third cousins.

A

half for siblings one eighth for first cousins 1/32 for second cousins and 1/128 for third cousins

8
Q

What are the four characteristics of x-linked dominant pedigrees?

A

Show how the risk of cystic fibrosis with a normal risk of 1/25 increases in consanguinity with a first cousin., 1/25 times 8 (cousins have 1/8 probability to share a gene) equals 1/3 probability