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Flashcards in Mendelian Inheritance Deck (36)
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1

What do disease associated mutations do

Alter protein function as it will have a non functioning or missing protein

2

What causes sickle cell disease

Abnormal HB gene

3

What type of inheritance does sickle cell disease show

Autosomal recessive

4

Where is sickle cell disease most prevalent

Africa
Mediterranean
Middle-East
India

5

What does SCD do to RBCs

Causes them to become sickle shaped which causes pain, tissue damage,infection and even death

6

What kind of problems can SCD cause

Problems with anaesthesia
Also: severe pain, cold, dehydration, infections, jaundice, stroke, leg ulcers, eye problems and kidney problems

7

In a family pedigree what shape are the boys

Square

8

In a family pedigree what shape are the girls

Circle

9

What is it called hen there is a risk of 0

Population risk

10

What is the chance of having a carrier child when the mother and father are both carriers of an autosomal recessive disorder

1/2 (50%)

11

What is the chance of having an affected child when the mother and father are both carriers of an autosomal recessive disorder

1/4 (25%)

12

What is the chance of being a carrier when your mother and father are both carriers of an autosomal recessive disorder and you know you do not have the disorder (e.g. 23 years old and have no symptoms of the disease)

2/3 (66%)

13

What is the chance of being a carrier when the mother and father are both carriers of an autosomal recessive disorder and you know you do not have the disorder (e.g. 23 years old and have no symptoms of the disease)

2/3 (66%)

14

What is the chance of being unaffected when your mother and father are both carriers of an autosomal recessive disorder and you know you do not have the disorder (e.g. 23 years old and have no symptoms of the disease)

1/3 (33%)

15

What is the chance of having a carrier child when only one parent is a carrier of an autosomal recessive disorder

50%

16

What is the chance of having an unaffected child when only one parent is a carrier of an autosomal recessive disorder

50%

17

What is the chance of having an affected child when only one parent is a carrier of an autosomal recessive disorder

0%

18

What can CF affect

Sinuses
Lungs
Skin
Liver
Pancreas
Intestines
Reproductive organs

19

What happens to the airways in CF

Airway walls tend to have thick, sticky mucus which blocks the airway and they may have bacterial infections and blood in their mucus

20

What is the chance of a child being a carrier if the grandparents are both carriers (and mother is definitely unaffected) and the father is from the UK where there is a 1/25 chance of being a carrier

The child's mother's chance of being a carrier is 2/3
The child's father's chance of being a carrier is 1/25
So the chance of both of them being a carrier is 2/3 x 1/25 = 2/75
So the child's chance of being a carrier is 2/75 x 1/4 = 1/150
The child's chance of being a carrier is 1/150

21

What is the chance of a child being a carrier if the grandparents are both carriers (and mother is definitely unaffected) and the father is from the UK where there is a 1/25 chance of being a carrier

The child's mother's chance of being a carrier is 2/3
The child's father's chance of being a carrier is 1/25
So the chance of both of them being a carrier is 2/3 x 1/25 = 2/75
So the child's chance of being a carrier is 2/75 x 1/4 = 1/150
The child's chance of being a carrier is 1/150.

22

What is the chance of a child being a carrier when the child's maternal cousin (mother's nephew) has CF

The child's mother chance of being a carrier is 1/2 (as she either is a carrier or not and she definitely does not have the disease)
The child's father is ignored in this situation as it is very unlikely he has the disease
So the child's chance of being a carrier is 1/2 x 1/2 = 1/4

23

What is the chance of having a carrier child when the father is a carrier of an autosomal dominant disorder

1/2 (50%)

24

With autosomal dominant disorders can there be skipped generations

No

25

Can there be male to male transmission in autosomal dominant conditions

Yes

26

Is a male or female more likely to pass on autosomal dominant conditions

Equally transmitted by men and women

27

What type of disease is Huntington's disease

Autosomal dominant
Neurodegenerative

28

What type of inheritance does Duchenne Muscular Dystrophy have

X-linked

29

In X-linked inheritance, if the father is affected by a condition and the mother is not, what is the likely outcome for their children

The sons will not have the condition
All of the daughters will carry the gene

30

Why is it that in X-linked inheritance, when the father is affected by the condition the sons have only a population risk of obtaining the disorder

Because the mutation present in the father is on the X chromosome and the son is only obtaining the Y chromosome from the father and X from the mother