Final

Question 1

Euchromatin

Answer 1

Loosely coiled, genes expressed

Question 2

Heterochromatin

Answer 2

tightly coiled, genes not expressed

Question 3

Prader Willi Syndrome and Symptoms

Answer 3

• rare neuro developmental disorder
• symptoms; rapid weight gain, obesity, delayed developmental motor skills; reduced muscle tone, infertility due to underdeveloped sex organs
• early death by age 30 from obesity and related complications

Question 4

Prader Willi Syndrome genetic bases

Answer 4

• loss of genes located at 15q11-q13
• loss of functional paternal SNORD116
• SNORD116 paternally expressed, maternally imprinted

Question 5

Angelman Syndrome Symptoms

Answer 5

-neurodegenerative mental retardation, awkward gait, tremors, seizures, frequent uncontrolled outbursts or laughter and happy disposition

Question 6

Angelman Syndrome genetic basis

Answer 6

• Mutation; loss of genes located at 15q11-q13
• loss of UBE3A and ATP10A expression
• paternally imprinted, maternally expressed

Question 7

UBE3A codes for…

Answer 7

ubiquitin-protein ligase E3A

Question 8

XIST gene is responsible for…

Answer 8

The silencing of one X chromosome

Question 9

Characteristics of Inactivated X Chromosome

Answer 9

• highly condensed chromatin(Barr Body)
• nuclear envelope association
• XSIT RNA production

Question 10

Multiple Sclerosis and Symptoms

Answer 10

• autoimmune disease targeting myelin sheath of CNS
• Symptoms; depend on location of affected nerves; numbness or weakness in one or more limbs, partial or complete loss of vision, fatigue, dizziness

Question 11

True or False; multiple sclerosis is 2/3 times more likely in women than in men?

Answer 11

True

Question 12

Multiple Sclerosis Treatments

Answer 12

• Interferon Beta(cytokine); leads to reduction in disease activity, does not reverse damage
• Glatiramer; random tetramer of 4 amino acids in myelin basic protein, act as decoy, diverting autoimmune response away from myelin
• Cortico Steroids; reduce inflammation

Question 13

Alzheimer’s Disease(AD) and Symptoms

Answer 13

• Severe impairment or loss of intellectual capacity and personality integration, due to loss of or damage to neurons in the brain
• Symptoms; inability to create new memories and loss of short term memory, no accurate sense of time, lack of speech
• death a result of respiratory failure

Question 14

Genomic Imprinting

Answer 14

DNA methylation of Cytosine at CpG island is principle means of imprinting

Question 15

Features of AD

Answer 15

• loss of synapses and neurons within certain areas of brain
• senile plaques accumulate outside of neurons in brain
• aggregations of NFTs within cell body and dendrites in the brain

Question 16

Synaptic Pruning happens in what disease?

Answer 16

AD, decreased synapses

Question 17

amyloid beta protein derived from what protein?

Answer 17

Amyloid precursor protein(APP)

Question 18

What two enzymes cut APP and what two proteins are generated?

Answer 18

Enzymes; beta-secretase and y-secretase

Proteins generated; Amyloid-beta40 and Amyloid-beta42

Question 19

MAPT gene encodes what protein?

Answer 19

Tau protein

Question 20

Function of Tau protein?

Answer 20

helps to maintain stability of microtubules which are important for vesicle transport up and down axons

Question 21

What 3 gene mutations represent 50% of familial EOAD?

Answer 21

APP, PS1, and PS2

Question 22

Presenilin Mutations

Answer 22

• leads to the increase in the ration of amyloid beta42 produced compared to amyloid beta40
• amyloid beta42 more likely to aggregate to form plaques in the brain than amyloid beta 40

Question 23

Genetic risk factors of LOAD

Answer 23

-ApoE4; accounts for 10-20% of LOAD risk

Question 24

Amyloid Hyposthesis

Answer 24

-amyloid beta proteotoxic stress triggers hyperphosphorlation and aggregation of microtubule associated protein tau, leading to neurofibrillary tangles(NFTs) in AD

Question 25

Ligand for DR6 signaling that promotes cell death?

Answer 25

N-APP binds to DR6 to trigger degeneration through caspase 6 in axons and caspase 3 in cell bodies
-AD

Question 26

Parkinsons Disease(PD) and Symptoms

Answer 26

• 2nd most common neurodegenerative disease

- PD symptoms; tremors, rigidity, difficulty walking, talking

Question 27

Changes in the PD brain

Answer 27

• diminished Substantia Nigra

- dopaminergic neurons in nigro-striatial pathway degenerate for unknown reasons

Question 28

What do striatal neurons release?

Answer 28

Dopamine to the striatum

Question 29

Causes of PD

Answer 29

-present in sporadic fashion
-PARK 1 and PARK 8; alpha-synuclein is inherently prone to misfold and to aggregate, which is major component of Lewy body
PARK 2; Parkin, impaired protein degradation
PARK 6; PINK 1, a deficiency in this protein leads to shortening, swelling, and fragmentation of mitochondria

Question 30

PD Treatment

Answer 30

-Levadopa; precursor of dopamine
Carbidopa; inhibitor of dopamine decarboxylase; important for producing dopamine from Levadopa; Carbidopa delays conversion of levadopa into dopamine until it reaches brain

Question 31

Huntington Disease(HD)

Answer 31

• localized in 4p16.3
• huntington gene has uninterrupted stretch of CAG/GTC repeats in the first exon
• HD patients have 40 or more repeats
• CAG repeats in DNA are inherently unstable

Question 32

How does CAG repeat expansion lead to neurodengeneration

Answer 32

• misfolding of expanded polyglutamine tracts

- aggregation of nuclear inclusions

Question 33

HD symptoms

Answer 33

-lose function of body

Question 34

Transmissible Spongiform Encephalopathies(TSE)

Answer 34

• progessive neurodegenerative diorders that affect humans and animals; caused by Prions
• produces spongiform changes in the brain

Question 35

Spongiform changes in brain due to Prions

Answer 35

-brain vaculolation, astrogliosis, neuornal apoptosis, accumulation of misfolded plaques

Question 36

What is it that CAG/GTC repeats greater than 40 are inherently unstable?

Answer 36

1) unequal recombination

2) replication slippage