Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Term 2 > Genetics Post-Midterm > Flashcards

Genetics Post-Midterm Flashcards

1
Q

Alpha thalassemia

A

Alpha: Multiple globin genes in clusters on Ch. 11 & 16; Sites arose due to duplications in evolutionary past. Ch 16 w/ alpha-cluster. Because of repetitive structure of alpha-structure, deletions are common diseases causing mechanism for alpha-thalassemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Beta thalassemia

A

Beta: decreased or absent beta-globin protein; decreased HbA (HbF = 2 alpha, 2 gamma); leads to RBC destruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Fragile X Syndrome

A

CGG repeat; more methylation because more GC-islands

*Decreased expression of FMR1 gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

3 major methods of duplications in the genome

A
  1. STR/VNTR
  2. Transposons (Alu – SINES/LINES)
  3. Pseudogenes – vestigal, duplicated, processed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are pseudogenes? What are the 3 types?

A

Pseudogenes are dysfunctional relatives of genes that have lost their protein-coding ability or are otherwise no longer expressed in the cell

  1. Vestigal
  2. Duplicated, unexpressed
  3. Processed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are processed pseudogenes?

A

Introns removed, normal poly-A tail. Reverse transcription yields pseudogene w/o introns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Most repetitive DNA in genome is __________________________ sequence

A

Transposon (LINES, SINES)

  • Jumping genes: can integrate in critical spot in genome, disrupt gene and cause disease
  • Can lead to misalignment during meiosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does red-green color blindness happen?

A

Unequal intragenic recombination between pairs of X chromosomes during meiosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 3 different DNA microarray methods?

A

CGH
SNP
cDNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is haplotype?

A

Combinations of alleles at different loci on chromosomes that are transmitted together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is an example of a vestigal gene?

A

Vitamin C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the HapMap? What is the key research question?

A

Looks for genetic variation in individuals without sequencing entire individual genomes
i.e. What markers segregate with this disease phenotype?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the transcriptome?

A

All the mRNA produced in a particular cell under a particular condition; isolate mRNA, label with cDNA, hybridize to expression microarray

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is proteomics?

A

Attempt to look at protein fingerprint of a cell; genes with multiple start sites, RNA editiong, modified protein complexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the major challenge to proteomics?

A

Difficult to ID proteins at very low concentrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the two main tools of proteomics?

A

2D-gel electrophoresis

Mass spectometry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is epigenomics?

A

Studying DNA methylation patterns on CG repeat islands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

T/F Chromosomal abnormalities account for a large number of spontaneous abortions

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the 2 categories/types of chromosomal abnormalities?

A
  1. Numerical

2. Structural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 2 major numerical -ploidy of chromosomal abnormalities?

A
  1. Euploidy / multiples of 23 (incompatible with life)

2. Aneuploidy (+/- chromosomes, i.e. monosomy, trisomy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is an exception to the rule that monosomy results in death?

A

Turner syndrome (45, X)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Differentiate between tripolidy and trisomy.

A

Triploidy (69, XXY)

Trisomy (47 chromosomes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Differentiate between sex-chromosome aneuploidy and autosomal aneuploidy.

A

Sex: Turner (X), Klinefelter (XXY)
Autosome: Trisomy 21 (Down), 18 (Edward), 13 (Patau)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Nondisjunction can cause 5 major diseases

A

Trisomy 12, 18, 21

Turner, Klinefelter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Nondisjunction is most common in MI/MII in males/females

A

MI, females

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

An increasing risk of what disorder results with increasing maternal age?

A

Trisomy 21: Down Syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Trisomy 21

A

Down syndrome
*Most common, short, intellectual disability, single palmar crease, congenital heart defect, Alzheimers, depressed nasal bridge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Trisomy 18

A

Edward

*Clenched fist, rocker bottom feet, heart, micro

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Trisomy 13

A

Patau

*Polydactly, cleft lip, cardiac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Turner Syndrome

A

45,X – female mosaics!

Short, webbed neck, amenhorrea, streak ovaries, gonadal dysgenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Klinefelter Syndrome

A

47, XXY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Klinefelter Syndrome will not happen in MI/M2 males/females

A

M2 males

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

XXX phenotype will not occur in M1/M2 males/females

A

M1 males

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the effect of inversions during crossover in meiosis?

A

Duplication or deletion of genetic material

Acentric (no centromere) or Dicentric (2 centromeres) are not viable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

A radiation worker lose genetic material at the terminal ends of her chromosomes and they fused to form a…

A

Ring chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is an isochromosome?

A

Loss of 1 arm and duplication of other arm (2p’s or 2q’s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

X-isochromosome i(X)

A

Can occur in children with Turner; 2 long arms of X chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the two types of inversions in a chromosome?

A

Pericentric: involves centromere
Paracentric: does not involve centromere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Differentiate between reciprocal and Robertsonian translocation.

A

Reciprocal: genetic exchange between non-homologs
Robertsonian: acrocentric chromosomes 13,14,15,21,22

Alternate (Balanced) or Adjacent (unbalanced)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

2 large deletion genetic conditions

A
  1. Wolf-Hirschorn 4p

2. Cri du Chat 5p

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

With what tests can you examine for a microdeletion?

A

FISH or CGH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

4 microdeletion syndromes

A
  1. Angelman (15q11)
  2. Prader-Willi (15q11)
  3. DiGeorge (22q11)
  4. WAGR syndrome (11) Wilms tumor, aniridia, GU, retardation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Philadelphia chromosome

A

Philadelphia chromosome or Philadelphia translocation is a specific chromosomal abnormality that is associated with chronic myelogenous leukemia (CML). It is the result of a reciprocal translocation between chromosome 9 and 22, and is specifically designated t(9;22)(q34;q11)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

The t(8,14) translocation is associated with…

A

Burkitt’s Leukemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Which are the acrocentric chromosomes?

A

13,14,15,21,22

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What are the 4 major types of genetic disorders?

A
  1. Single gene
  2. Chromosomal
  3. Mitochondrial
  4. Complex: genes + environment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Explain additive alleles.

A

Number of dominant alleles determine the phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Describe the polygenic theory of quantitative traits.

A

What you see in “real life”; a normal distribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

The more genes that control a trait may determine…

A

The extent of the phenotype observed

* More genes = broader range of phenotypes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What percentage of height is genetically determined?

A

20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Describe the genetic liability model.

A

A discontinuous phenotype (affected/not affected) in the context of continuous variation

  • All factors that contribute to the disease = liability
  • Genes and environment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

For a family with “bad” genes, the distribution of the liability-threshold model is right/left shifted?

A

Right shifted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Within a family, who (first, second, third-degree) relatives has a greater familial relative risk? The risk drops by ____ in every succeeding degree

A

First-degree relatives

* Risk drops by 1/2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is lambda t (familial aggregation/relative risk)? The larger lambda T…

A

Freq in family/Freq in general population; greater the risk in the family

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Can the genetic liability model be used to identify recurrence risk in families?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What are features of complex/multifactorial inheritance diseases?

A
  • Non-Mendelian
  • Aggregates in families
  • Close relatives
  • Multiple genes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

For a multifactorial disease, can risk change for children?

A

Yes – more first degree relatives, greater risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Is pyloric stenosis more common in boys or girls?

A

Boys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

For women to have CVD pre-menopause, they have more/less contributing factors than do men.

A

More

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Identifying the genetic component of a complex disease will determine the ________________ of the disease.

A

Heritibility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What are the tools to study genetic and environmental factors of a complex disease?

A

Migration studies, family, twin, adoption, association studies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

A higher heritibility, a greater/lesser contribution of genetics?

A

Greater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

With monozygotic twins, the greater the discordance, the lesser/greater environmental input?

A

Greater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

With respect to concordance, a condition with high concordance in monozygotic and dizygotic twins has a greater environmental or genetic role?

A

Environmental

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Heteroplasmy

A

Characteristic of mitochondrial inheritance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

How can we identify genes that contribute to multifactorial inheritance?

A
  1. Allele sharing (siblings, families)

2. Population-based association studies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is IBD, or identical-by-descent?

A

Allele-sharing methods involve testing whether affected relatives inherit the same genomic regions (called identical by descent) more often than expected under Mendelian segregation.

Affected sibling pairs – normally share 50% of genes, but analysis of affected pairs may reveal that a trait-causing gene is present >50% of time, highlighting the importance of this gene in the phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

T/F Population-based association studies are case-control studies

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What is the caveat with population-based associated studies?

A

They give only correlation between the presence of a marker and the occurrence of the disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is the objective of genome-wide-association studies?

A

Compare genomes of people with illness to unaffected people

* Look for relationships between SNP’s and disease phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

With respect to common disease, rare variant hypothesis, rare variants have arisen more recently or ancient?

A

More recently

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

On what chromosome is the APOE4 gene?

A 
Chromosome 19 (Alzheimers)
*Involved in lipoprotein metabolism; binds beta-amyloid and reduces its solubility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What are the prevailing arguments about neural tube defects being genetic/environmental?

A

Genetic: 3% risk of having a second child with NTD
Environmental: folate reduces risk by 70% & down to 1% for a second child

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Who is at highest risk for obesity?

A

Non-hispanic blacks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Differentiate between DNA damage and mutation.

A

Damage is repaired before replication

Mutation is incorporated, not fixed, and replicated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Describe the 2 major classes of spontaneous mutation

A
  1. Error of replication (S phase)

2. Spontaneous lesion (resting cell)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What are the 2 major classes of DNA mutation

A
  1. Spontaneous

2. Induced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

How is DNA repaired?

A

By 3’ 5’ DNA polymerase exonuclease activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What are the 3 major types of spontaneous lesions (as a subclass of spontaneous mutations)?

A
  1. Depurination
  2. Deamination
  3. Oxidative damage
80
Q

Where is a mutational hotspot?

A

5-methyl-cytosine deaminated to thymidine

81
Q

What is a mutagen?

A

Increases frequency of normal mutation (mismatches, depurination, etc.)

82
Q

True or False: Ionizing radiation can cause many types of cellular damage and lead to heritable mutations

A

True

83
Q

Which of the following is the most common error in DNA? Depurination, deamination, methylation

A

Depurination

84
Q

Differentiate between nucleotide excision, base excision, mismatch repair

A

Nucleotide: up to 30 bases (i.e. UV damage)
Base excision: single base (i.e. methylation)
Mismatch repair: mismatched bases (i.e. tautomers)

85
Q

Excision repair involves 3 steps

A
  1. Recognition
  2. Removal (glycosylase and then endonuclease)
  3. Replacement (ligase seal)
86
Q

What is the AR disorder that involves extreme sun sensitivity?

A

Xeroderma pigmentosum

87
Q

Mismatch repair is pre- or post- replicative?

A

Post-replicative

88
Q

What type of DNA repair is important for triplet repeat expansion disorders?

A

Mismatch repair

89
Q

How does the cell know which DNA is the correct one to repair? (Proks and Euks)

A

Proks: methylated strand
Euks: methylation +/- host machinery

90
Q

A mutation of mismatch repair genes MSH2 and MLH1 can result in…

A

Hereditary nonpolyposis colon cancer

91
Q

Which gene is central to a large number of repair processes, including damage sensor, chromatin remodeling, bloom helicase, MMR, cell cycle control, regulation of apoptosis?

A

BRCA1

92
Q

Longterm consequences of DNA damage

A

Aging and cancer

93
Q

Ataxia telangrectasia

Louis-Bar syndrome

A

A-T is caused by a defect in the ATM gene, which is responsible for managing the cell’s response to multiple forms of stress including double-strand breaks in DNA. In simple terms, the protein produced by the ATM gene recognizes that there is a break in DNA, recruits other proteins to fix the break, and stops the cell from making new DNA until the repair is complete

94
Q

2 disorders associated with chromosomal breaks

A 
Bloom syndrome (15q26.1)
Fanconi Anemia (N8)
95
Q

Term for the ability of chemicals to exist as mixtures of 2 inconvertible isomers

A

Tautomerism

96
Q

DNA repair can involve 3 processes

A
  1. Nucleotide excision
  2. Base excision
  3. Mismatch repair (MMR)
97
Q

Does the threshold model apply for cancer?

A

No

98
Q

Tumor progression results from waves of __________ followed by ______________.

A

Mutation; clonal expansion

99
Q

There are several alterations in malignant transformation. What are they?

A
  1. Increased survival and growth
  2. Metastasis (loss cell-to-cell adhesion)
  3. Increased mutation rate (breakdown host DNA repair)
  4. Energy supply (angiogenesis)
100
Q

Are cancers derived from a single cell?

A

Most no (polyclonal); some are monoclonal

101
Q

What is the story behind X-inactivation and cancer?

A

All cancer cells have the same X-inactivated

102
Q

How can we monitor the effetiveness of cancer therapy?

A

Look at cells pre- and post- treatment to see if they still contain the chromosomal abberation

103
Q

Multiple myeloma is a malignancy of the ____ cell. All myeloma cells in a patient produce ___________.

A

B cell

Same antibody molecule

104
Q

What are the 3 major categories of cancer causing genes?

A
  1. Proto-oncogenes
  2. Tumor suppressor genes
  3. Repair genes
105
Q

Match the following:
Gain of function/Loss of function
Proto-oncogenes; tumor suppressor genes

A

Gain: proto-oncogenes
Loss: tumor suppressor genes

106
Q

What is the mutant form of proto-oncogenes?

A

Oncogenes

107
Q

Mutant oncogene or production of large amount of a protein that stimulates cell division can lead to:

A

Cancer

108
Q

Oncogenic activation by translocation can result in (2)

A
  1. Chronic myeloid leukemia

2. Burkitt lymphoma

109
Q

What is the genetics of chronic myeloid leukemia?

A

Philly chromosome translocation: t(9,22)

* Unregulated tyrosine kinase

110
Q

The nuclear protein responsible for stimulating cell cycle at the G1/S transition

A

MYC

111
Q

What is the genetics of Burkitt Lymphoma?

A

Overproduction of MYC (rapid cell division); t(8.14)

112
Q

The MAP kinase pathway, which is stimulated by growth factors….

A

Results in phosphorylation of serine and threonine, which drives cell division

113
Q

Constitutive activity of a proto-oncogene can result from:

A

point mutation; truncation/deletion

114
Q

Match:
Chromosome 9, 22
BCR; ABL

A

Ch. 9: ABL

Ch. 11: BCR

115
Q

Imatinib mesylate

A

A powerful inhibitor of tyrosine kinase

* Effective against BCR/ACL fusion protein

116
Q

Oncogenesis depends on RAS over/under-activity

* RAS is a _______-involved in cell proliferation

A

Hyperactivity

GTP-ase

117
Q

RAS-GTP vs. RAS-GDP

A

Active vs. inactive

118
Q

What is double minutes?

A

Extra-chromosomal fragments of DNA containing an amplified region of the chromosome

119
Q

EGFR is seen in advanced….

A

gliomas
* EGFR is amplified as double minute chromosome (extra-chromosomal fragments of DNA containing an amplified region of the chromosome)

120
Q

Example of an autosomal dominant cancer

A

Wilms’ tumor
* Results from loss of function in the WT1 gene on chromosome 11, which encodes for a transcription factor important in the control of cell growth/differentiation

121
Q

What is the two-hit hypothesis?

A

Need to lose 2 tumor suppressor genes for cancer to develop

122
Q

Differentiate between sporadic/familial cancers for the 2 hit hypothesis.

A

Sporadic: 2 hits
Familial: 1 hit (b/c 1 is inherited)

123
Q

The second hit (in a familial cancer is not a simple mutation, but a……

A

Loss of heterozygosity

124
Q

Recently, it has been discovered that the “second hit” can result from…..

A

Aberrent methylation

125
Q

HER2

A

Amplification

126
Q

MYC

A

Overexpression IgH

127
Q

BCR/ABL

A

Translocation/tyrosine kinase

128
Q

RAS

A

Mutation

129
Q

BRCA

A

Mutation

130
Q

APC

A

Familial adeomatous polyposis (bowel ca) (TSG)

131
Q

VHL

A

Von Hippel-Lindau syndrome (hemangioblastoma, pheo, renal cell carcinoma) (TSG)

132
Q

TP53

A

Li-Fraumeni Syndrome (Soft tissue sarcoma) (TSG)

133
Q

NF1/2

A

Neurogibromatosis 1/2 (schwannoma, meningioma) (TSG)

134
Q

TSC1/2

A

Tuberous sclerosis complex (TSG)

135
Q

WT1

A

WAGR (Wilms tumor, aniridia, GU, growth) (TSG)

136
Q

MSH1/2, PMS1/2

A

Hereditary non-polyposis colon cancer (TSG)

137
Q

MEN1

A

Multiple endocrine neoplasia (TSG)

138
Q

A loss of Rb or a mutant Rb leads to…

A

Inability of Rb to bind to E2F and hence, unregulated cell growth (G1/S)

139
Q

Rb is normally bound to _________ which stimulates/prevents cell growth.

A

E2F; prevents

140
Q

Describe the effect of phosphorylating Rb

A

Inactivates it; allows E2F to stimulate cell divison

141
Q

Differentiate between sporadic and Mendelian retinoblastoma.

A

Mendelian: Requires a second hit; Bilateral, early, multi-tumor (30%)
Sporadic: 2 somatic mutations; unilateral, later onset, single tumor

142
Q

The 4 genes that regulate the phosphorylation of Rb

A
  1. p16
  2. CLND
  3. CDK4
  4. Rb/E2F
143
Q

p16

A

CDK inhibitor (Rb)

144
Q

CLnD/CDK4 complex

A

Inactivates Rb by phosphorylation

145
Q

p53 is a _________________________ that controls both _______________ and __________________

A

Tumor supressor gene

Cell growth; cell death

146
Q

Why is a mutation of p53 bad?

A

Uncontrolled cell growth & greater mutation (cancer progression)

147
Q

LiFraumeni syndrome

A

Inherited mutation of p53

  • 1st hit: mom
  • 2nd hit: LOH/somatic
    • Childhood cancer – breast, bone, brain
148
Q

p53 regulates the intrinsic apoptosis pathway in 3 ways:

A
  1. pro-apotosis BCL-2
  2. FAS receptor/CD95
  3. IGFBP-3 (sequesters insulin growth factor and prevents it from interacting with receptor)
149
Q

What what pathway is APC associated? What is a disease associated with this mutation?

A

Fam adenomatous polyposis

  • APC normally degrades beta-catenin which inhibits growth (WNT signalling pathway)
  • Without APC, unregulated growth (B-catenin – TCF4 pathway)
150
Q

Yes WNT signal

No WNT signal

A

Yes – growth

No – no growth (because of APC)

151
Q

RAS: tumor suppressor or proto-oncogene?

A

Proto-oncogene

152
Q

Which disease progresses more rapidly: FAP or HNPCC

A

HNPCC

153
Q

Which is the gate-keeper and which is the caretaker? APC, MMR genes

A

Gatekeeper: APC
Caretaker: MMR genes

154
Q

What cancer is associated with microsatellite instability?

A

HNPCC

155
Q

T/F BRCA1 demonstrates allelic heterogeneity.

A

True

156
Q

How do you best describe the heterogeneous relationship between BRCA1 and 2

A

Locus heterogeneity

157
Q

What treatment is effective for Her2+ breast cancer?

A

Herceptin // prevents HER2- epidermal growth factor interaction

158
Q

What is the role of microRNA mutations in cancer?

A

Not enough – enhanced oncogenes

Too much – suppression of tumor suppressors

158
Q

Differentiate between inherited/sporadic cancers with respect to age of onset, multiplicity, paired organs, types of tumors, family pattern, markers, degree of risk

A

Inherited – earlier, manu tumors, bilateral, familial associations

159
Q

Differentiate between inherited/sporadic cancers with respect to age of onset, multiplicity, paired organs, types of tumors, family pattern, markers, degree of risk

A

Inherited – earlier, manu tumors, bilateral, familial associations

161
Q

Imatinib mesylate can be used to treat

A

Philadelphia + CML

162
Q

HIV

A

“Facilitated apoptosis”

Inactivation of BCL-2; FAS pathway, viral proteins inducing apoptosis (tat, nef, epr)

163
Q

Differentiate between BCL-2 and BAX/BAK

A

BCL-2: anti-apoptosis

BAX/BAK: pro-apoptosis

164
Q

Which process requires energy: necrosis or apoptosis?

A

Apoptosis

165
Q

Differentiate between the intrinsic and extrinsic pathways of apoptosis (objective and caspases)

A

Intrinsic: genotoxic damage (caspase 9, 2)
Extrinsic: unwanted cells during development, virally infected cells (caspase 8, 10)

166
Q

What are the steps/key players of the intrinsic apoptosis pathway?

A
  1. p53 phosphorylation
  2. BAX, p21
  3. Cytochrome c (mito)
  4. APAF-1 (binds apoptosome)
  5. Procaspase –> Caspase
167
Q

What are the steps/key players of the extrinsic apoptosis pathway?

A
  1. T-killer cell expresses FAS
  2. Bind to FAS death receptor
  3. Adaptor molecules
  4. Procaspase – DISC
  5. Caspase
168
Q

The 3 major components of the apoptosis pathway

A
  1. Regulators – BCL2 (anti); BAK, BAX (pro)
  2. Adaptors – bind to procaspase
  3. Effectors – caspases (laminins, DNA repair)
169
Q

The 3 methods to look for apoptosis in vivo

A
  1. DNA ladder / fragmentation
  2. Change in membrane structure (Ab- Annexin 5 translocated to outer cell membrane)
  3. Caspase assay
170
Q

What can you use to detect DNA fragmentation in situ?

A

TUNL (terminal transferase dUTP nick end labeling)

171
Q

Extracellular survival factors (up or down) regulate apoptosis

A

Down

172
Q

Too much apoptosis leads to…

A

Alzheimers, HIV

173
Q

Too little apoptosis leads to…

A

cancer

174
Q

Pyknosis

A

Condensation of chromatin (apoptosis)

175
Q

Karyorrhexis

A

Discontinuous nuclear envelope (apoptosis)

176
Q

What are the 2 types of genetic screening?

A
  1. Targeted (carriers, late penetrance conditions)

2. Population (prenatal, neonatal)

177
Q

Prenatal screening is done to test for 3 conditions

A

Trisomy 21, 18, neural tube defects

178
Q

What are the 2 major types of prenatal screening?

A
  1. Non-invasive – Maternal serum, ultrasound

2. Invasive – CVS, Amnio

179
Q

Trisomy 21 on pre-natal screening

A

High B-HCG, inhibin A

180
Q

Trisomy 18 and 13 on pre-natal screening

A

All lower

181
Q

NTD on pre-natal screening

A

High AFP

182
Q

At what week can an ultrasound reveal nuchal translucency?

A

18 weeks

183
Q

Which can you do first: CVS or Amnio?

A

CVS

184
Q

To test for CF in the blood, what types of test do you do?

A

Immuno-reactive trypsinogen

185
Q

BCHE gene defect

A

AR

-Succinylcholine metabolism

186
Q

Toxicity associated with n-acyltransferase

A

Isoniazid - neuropathy, hepatotoxicity
Hydralazine (HTN), procainamide (arrhythmia)  SLE
Sulfonamides  hemolytic anemia, SLE

187
Q

CYP2D6 deficiency

A

CYP450 superfamily

* Anti-depressants, antiarrhythmic, analgesics

188
Q

Thiopurine s-methyltransferase polymorphism

A

Low TPMT  toxicity and myelosuppression when treated with standard doses of thiopurine, i.e. azathioprine, mercaptopurine (anti-cancer drugs)

189
Q

Warfarin

A

-S- Warfarin more potent than R-Warfarin
CYP2C9 metabolizes S-Warfarin
Underactive CYP2C9 – lower doses of warfarin, higher dose risk of bleeding
* Also Vit K epoxide reductase deficiency – normally this enzyme is inhibited by Warfarin

190
Q

Malignant hyperthermia

A

AD
Defect in RYR1 - Ryanodine receptor
Elevated release of Ca2+ from SR of skeletal muscle following inhalation anesthesia (halothane)

191
Q

Differentiate between somatic cell nuclear transfer and induced pluripotent stem cells

A

SCNT: correct mutation in vitro, nucleus transferred to egg or embryonic stem cells

IPPSC: reprogram a somatic cell to become an embryonic stem cell

192
Q

What signal can send something to a lysosome?

A

Mannose

193
Q

With what is urea cycle treated?

A

Sodium benzoate (diverts ammonia to glycine and excretion of hippurate)

194
Q

What is PEGylation?

A

adds stability to a protein

195
Q

With what can PKU1 be treated?

A

Sapropterin – pharmacologic doses of BH4

Term 2 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions