Trinucleotide Repeats

Question 1

What is the trinucleotide repeat in Huntington’s Disease?

Answer 1

CAG

Question 2

What is the inheritance for Huntington’s Disease?

Answer 2

Autosomal Dominant

Question 3

What are the symptoms of Huntington’s disease?

Answer 3

1) Aggression
2) Psychosis
3) Chorea
4) Dementia

Question 4

What are the lab findings in Huntington’s disease?

Answer 4

1) Increased Dopamine
2) Decreased Acetylcholine
3) Decreased GABA
4) Decreased Caudate

Question 5

Mneumonic for Huntington’s Disease?

Answer 5

Can’t Aim Great when you HUNT 4 AN animal.

(CAG)
(Chromosome 4)
(Genetic ANticipation)
(Can’t aim great = Chorea)

Question 6

Which chromosome has a problem in Huntington’s Disease?

Answer 6

Chromosome 4

Question 7

Genetic anticipation is found in which disease?

Answer 7

Huntington’s disease

Question 8

What is the trinucleotide repeat for Fragile X Syndrome?

Answer 8

CGG

Question 9

What is the mode of inheritance of Fragile X Syndrome?

Answer 9

X-Linked Dominant

Question 10

What are the symptoms of Fragile X Syndrome?

Answer 10

1) Macroorchidism!!!!!!!
2) Intellectual disability
3) Long face
4) Large ears

Question 11

Mneumonic for Fragile X Syndrome)

Answer 11

Congenitally Giant Gonads

(CGG)

Question 12

What is the trinucleotide repeat in Friedreich’s Ataxia?

Answer 12

GAA

Question 13

What is the mode of inheritance for Friedreich’s Ataxia?

Answer 13

Autosomal Recessive

Question 14

What are the symptoms of Friedreich’s Ataxia?

Answer 14

1) Ataxia/Staggering gait
2) Hammer toes
3) Pes cavus
4) Scoliosis

Question 15

What is the most common cause of death in Friedreich’s Ataxia?

Answer 15

Hypertrophic Cardiomyopathy

Question 16

Which gene is defective in Friedreich’s Ataxia?

Answer 16

Frataxin gene

Question 17

What is the Frataxin gene normally responsible for?

Answer 17

Shuffling iron into cells

Question 18

What happens if the Frataxin gene doesn’t work properly?

Answer 18

Too much iron shuffles into cells

Question 19

Which part of the cell takes the MOST damage when the Frataxin gene doesn’t work properly?

Answer 19

Mitochondria

Question 20

Pathophysiology of Friedreich’s Ataxia?

Answer 20

An abnormal iron accumulation due to a defect in the Frataxin gene

Question 21

What is the trinucleotide repeat in Myotonic Dystrophy (Type 1)?

Answer 21

CTG

Question 22

What is the mode of inheritance of Myotonic Dystrophy (Type 1)?

Answer 22

Autosomal dominant

Question 23

What is the KEY symptom of Myotonic Dystrophy (Type 1)?

Answer 23

Distal extremity weakness (usually in forearms and hands)

Question 24

What are the main findings in Myotonic Dystrophy (Type 1)?

Answer 24

1) Cataracts
2) Testicular atrophy
3) Gammaglobinemia

Question 25

How would a question appear that would give away Myotonic Dystrophy (Type 1)?

Answer 25

1) Can’t release a doorknob
2) Can’t release a screwdriver
3) Can’t let go of somebody’s hand
(Can’t stop contraction)