Session 17-Genetics In Medicine Flashcards Preview

Semester 1-MCBG > Session 17-Genetics In Medicine > Flashcards

Flashcards in Session 17-Genetics In Medicine Deck (20):
1

What are the symptoms of sickle cell anaemia (SCA)? (3)

Anaemia
Fever
Severe pain

2

Which single DNA mutation causes SCA?

A to T in the beta-globin gene

3

How does the single DNA mutation cause a change in the beta-globin protein?

Position 6 in the AA chain from Glu to Val

4

True or false: only one copy of beta-globin needs to be mutated to cause SCA

FALSE-both have to because it is an autosomal recessive disorder

5

True or false: individuals who are heterozygous for SCA (sickle cell trait) are resistant to malaria

TRUE

6

What is epigenetics?

Complex web of gene regulation

7

True or false: foetal gamma globin is turned off after birth and adult beta globin is turned on

TRUE

8

Can gamma globin be kept switched on?

Yes, it has no impact on health but would prevent SCA

9

Which protein binds to DNA and switches off the gamma globin gene?

Protein BCL11A (repressor)

10

What does HSPC stand for and what can it be used in?

Haemopoietic stem and progenitor cells
Used in gene editing therapy for SCA

11

What is Huntington's disease (HD)?

Inherited neurodegenerative disease

12

What are the symptoms of HD? (4)

Seizures
Abnormal gait
Personality change
Dementia

13

True or false: the mutation causing HD is a short tandem repeat (STR) of CGA

FALSE - it is a STR of CAG

14

True or false: HD is autosomal recessive

FALSE - autosomal dominant

15

What is the age of onset of HD?

40-50

16

True or false: from generation to generation, age of onset of HD becomes earlier and symptoms become more severe

TRUE

17

How is age of onset of HD affected by CAG repeat length?

Negative correlation - as CAG repeat length increases, age of onset decreases but still lots of variation

18

What influences age of onset of HD?

Multifactorial - CAG repeat length as well as other genetic factors (one on chromosome 8 and two on chromosome 15)

19

What causes developmental disorders?

Environment (infection, maternal alcohol etc)
New mutation in gene

20

True or false: developmental disorders can be found by sequencing the exome (exons of genome)

TRUE