U5: CHROMOSOMAL ABERRATIONS + DELETION Flashcards
(129 cards)
1
Q
Tiny changes in the chromosome
A
Mutations
2
Q
Structural or numerical change in the chromosome seen even in simple staining techniques
A
Aberrations
3
Q
Test for copy number repeats or loss
A
CGH
4
Q
There are variations from the wild-type condition in either chromosome structure or chromosome number
A
Chromosomal aberrations
5
Q
This mechanism is seen when genes are inherited only from the mother.
A
Genomic imprinting
6
Q
Special form of duplication seen in Huntington’s Disease.
A
Expansion of trinucleotide repeats
7
Q
Variation in Chromosome Structure
A
Deletion
Duplication
Inversion
Translocation
8
Q
Three broad categories of chromosome mutations
A
Chromosome Rearrangements
Aneuploidy
Polyploidy
9
Q
Overall chromosome number is unaffected, but large pieces of chromosomes move
A
Chromosome Rearrangements
10
Q
Trisomy 21, Klinefelter’s Syndrome, Turner’s Syndrome
A
Aneuploidy
10
Q
These mutations alter chromosome structure
A
Chromosome Rearrangements
11
Q
One or more individual chromosome pair has its number altered (either add or subtract)
A
Aneuploidy
12
Q
One or more complete chromosome sets are added
A
Polyploidy
13
Q
3n, 4n
A
Polyploidy
14
Q
T/F: Aneuploidies present as one or more of the chromosomes in the pair.
A
True
15
Q
In what phase do aneuploidies occur?
A
Meiosis
16
Q
This refers to a pair of homologous chromosomes that has failed to separate or segregate at anaphase so both chromosomes of the pair pass to the same daughter cell.
A
Nondisjunction
17
Q
This refers to chromosomes which does not properly separate, leaving one or two sex cells with an extra chromosome or with one less chromosome.
A
Nondisjunction
18
Q
This can occur after nondisjunction during the mitotic cell division.
A
Mosaicism
19
Q
Chromosomal disorders caused by this results in one line of cells with a chromosomal aberration while other lines may stay unchanged.
A
Mosaicism
20
Q
T/F: Egg with monosomic conditions do not proceed to further fertilization.
A
True
pag trisomy daw pwede pa
21
Q
2n + 1 = 7
A
Aneuploidy (Trisomy)
22
Q
3n = 9
A
Polyploidy (Autotriploid) / Triploidy
23
Q
2n = 6
A
Chromosome rearrangement (duplication)
24
Where can triploidies be found?
Plants
25
Chromosomal mutation that results in the doubling of a segment of a chromosome
Duplication
may nadadagdag lang
26
2n = 6
Chromosome rearrangement (Duplication)
27
Forms of Duplication
Tandem
Reverse
Terminal Tandem
28
This duplication is observed with the repeats in Huntington's Disease.
Tandem Duplication
29
This duplication is observed with inversed sequences.
Reverse Duplication
30
This duplication is observed in the tips.
Terminal Tandem Duplication
31
Unbalanced set of chromosomes, relative gene dosage is upset
Aneuploidy
32
Loss of a single chromosome copy
Monosomic
33
Extra copies of single chromosome
Polysomic
34
T/F: Most chromosome abnormalities are lethal, frequently in spontaneous abortions.
True
35
Exceptions of Lethal Chromosome Abnormalities
Trisomy 13, 18, 21, and Sex Chromosomes
36
T/F: An extra X or Y chromosome usually has a relatively severe effect.
False
mild effect
37
Mild effect of extra sex chromosome
1) X chromosome inactivation/Dosage Compensation
2) Not much (essential) on the Y
38
Part of a chromosome present twice
Duplication
39
ISCN stands for?
International System for Human Cytogenomic Nomenclature
40
Abbreviations: dup
Duplication
41
dup(17p12)
Charcot-Marie-Tooth type 1A
42
FORMATIVE: Symptoms of Charcot-Marie-Tooth Disease
- Hammertoes
- Muscle Weakness
- Foot Drop
- Paralysis
- Numbness or tingling
- Creeping sensation in the legs
43
Duplication that is one right after the other
Tandem duplication
44
Duplication that is repeated in another part of the chromosome (self explanatory daw)
Displaced Duplication
45
ABEFCD EFGH
Displaced duplication
45
ABCD EFEFGH
Tandem duplication
46
ABCD FEEFGH
Reverse duplication
47
T/F: Individuals can be homozygous or heterozygous for duplications, it can happen only on one or both sister chromatids.
True
48
Worst form of duplication
Homozygosity
consider dosage = more or lesser effect
49
The more or less there is will reflect on expression of phenotype
Dosage
50
Significant effects on an individual's phenotype is due to?
Unbalanced Gene Dosage
dapat di ka double dosage haha
51
In what phase of Meiosis does duplication arise in heterozygotes?
Prophase I and Synapsis
52
T/F: The duplicated region in Meiosis must loop out for synapsis to occur.
True
pag di nag loop, matatanggal yung region = loss of chromosomal content
53
Position Effect of Eye Size in Drosophilia
Duplication
54
T/F: 99% of duplications are often bad, and 1% of duplications allow evolution to proceed forward.
True
55
The process in which fetal hemoglobin was allowed to evolve.
in utero reproduction
56
easter egg!!
pag sinira m yng protein coding gene...
patay Ka!
- ian, 2024
duplicated genes lang ang paglaruan moh
57
T/F: Fetal hemoglobin is a result of duplication.
True
58
T/F: Fetus will still survive even if it shares a blood supply with the mother (adult hemoglobin.)
False
all hemoglobin (oxygen) will go straight to the mother since it is adult hemoglobin
59
Duplication result of extra #12 chromosome or usually a mixture of cells (mosaicism)
Pallister Killian Syndrome
60
Symptoms of Pallister Killian Syndrome
- Severe intellectual disability
- Poor muscle tone
- "Coarse" facial features
- Prominent forehead
61
T/F: People with Pallister Killian have a shortened lifespan, but may live up to their 40s.
True
62
Duplication of a small piece of Chromosome 17 in each cell
Potocki-Lupski syndrome
63
17p11.2
Potocki-Lupski syndrome
64
About 40% of babies with Potocki-Lupski present with?
heart defects
64
Symptoms of Potocki-Lupski
- hypotonia (weak muscle tone)
- dysphagia (swallowing difficulties)
- does not grow and gain weight
65
Multiple duplications/microdeletions of a CGG segment in the 5' untranslated region of the FMR1 gene on X chromosome.
Fragile X Syndrome
66
Xq27
Fragile X Syndrome
67
Syndrome with repeated trinucleotide segments and express penetrance
Fragile X Syndrome
68
6-40 repetitions
Weak Form
69
41-60 repetitions
Middle Form
70
61-200 repetitions
Strong Form
71
>200 repetitions
Full mutation/penetrance
72
T/F: The deleted segment in deletions can be located anywhere in the chromosome.
True
73
T/F: Fragile X Syndrome affects more women than men.
False
mas severe kay man kasi isa lang X nya
74
Symptoms of Fragile X Syndrome
- inherited mental retardation
- prognathism (small and long face, large ears)
75
Loss of segment of a chromosome
Deletion
76
How does deletion start?
Chromosomal breakage
77
Causes of Chromosomal Breakage
- Heat
- Ionizing radiation
- Viruses
- Transposable elements
- Errors in recombination
78
Examples of ionizing / high energy radiation
UV, X-ray, cosmic rays
79
These cause oncogenic or cancer cells.
Viruses
80
These are also known as jumping genes.
Transposable Elements
81
T/F: Deletion that spans the centromere causes a more fatal effect due to the chromosome being acentric.
True
82
Deletion that occurs towards the end of a chromosome
Terminal deletion
83
T/F: Deletion in the telomeric region does not affect gene expression.
True
pag may nasama from subtelomeric = incompatible na of life
84
Deletion that occurs from or in the interior of a chromosome.
Intercalary / Interstitial Deletion
85
Relatively small amount of deletion (up to 5mb that could include a dozen genes)
Microdeletion
86
Deletion that is most common cause of disease
Microdeletion
other deletions are large enough = incompatible of life
87
Deletion that is usually found in children with physical abnormalities
Microdeletion
88
T/F: Large deletions can be detected in karyotype as a shortened chromosome.
True
89
Centromeric deletion
No segregation during cell division
90
T/F: Recessive alleles express more readily when there are deletions.
True
no counteracting mechanism if deleted ang dominant gene
91
Abbreviations: -
Chromosome Deletions
92
Abbreviations: Δ (delta)
Microdeletions
93
Abbreviations: del
Deletions of Chromosome Parts
94
Deletion of number of pairs that is not evenly divisible by three
Frameshift mutation
95
Deletion that is evenly divisible by three
In-frame deletion
96
Genetic disorders from Deletions
- Male infertility
- Duchenne Muscular Dystrophy
- Cystic Fibrosis
- DiGeorge Syndrome
97
Deletions in SMN-encoding gene, and the most common genetic cause of infant death
Spinal Muscular Atrophy
98
Syndromes associated with both microdeletions and genomic imprinting
- Angelman syndrome
- Prader-Willi syndrome
99
5p-
Cri-du-chat Syndrome
100
Also known as "cry of the cat", severe mental retardation
Cri-du-chat Syndrome
101
11q-
Wilms tumor
102
Kidney tumors, genitals and urinary tract abnormalities
Wilms tumor
103
13q-
Retinoblastoma
104
Cancer of the eye, increased risk of other cancers
Retinoblastoma
105
15q-
Prader-Willi Syndrome
106
Weak slow growth in infants, Obesity or compulsive eating in children and adults
Prader-Willi Syndrome
107
ΔF508
Cystic Fibrosis
coding for Phenylalanine
108
T/F: Patients with cri-du-chat die on their first year of life or in early stages of life.
True
109
CLL stands for?
Chronic Lymphocytic Leukemia
110
-13q14
Chronic Lymphocytic Leukemia
111
Prader-Willi: What bands of Chromosome 15 are deleted in the long arm?
q11 and q13
112
Loss of OCA2 gene in Chromosome 15
Angelman syndrome
113
Have happy or excitable personalities, causes delayed development, intellectual disability and seizures (more on Maternal)
Angelman syndrome
114
2/3 deletion type
Duchenne Muscular Dystrophy
115
Change in sequence of codons and render the protein is abnormal
Frameshift mutation
116
T/F: Even if you do not delete protein coding genes, it might still have an effect since there is a possibility that it is a region that codes for transcription factors.
True
117
Expected to be alive at least 5 years after diagnosis
Wilms Tumor
118
This significantly influence the prognosis of disease
Type, Size, Location of Deletion
119
Also a product of the deletion of Retinoblastoma protein
Chronic Lymphocytic Leukemia (CLL)
120
Accumulation of B lymphocytes, increased abnormal antibodies
Chronic Lymphocytic Leukemia (CLL)
121
What makes B cells immortal?
Loss of apoptopic factors
122
This syndrome has no cure, and requires constant treatment.
Angelman syndrome
123
This is also related to Albinism.
OCA2 gene
124
This refers to when both alleles come from either maternal or paternal.
Uniparental disomy
125
More maternal syndrome
Angelman syndrome
126
More paternal syndrome
Prader-Willi Syndrome
