UNIT 5 Chromosomal Aberrations Flashcards
(115 cards)
1
Q
Chromosomal mutations is commonly known as?
A
Chromosomal aberrations
2
Q
The variation of chromosomal mutations come from the ____ condition in either chromosome structure or chromosome number.
A
Wild-type
3
Q
The two type of chromosomal abnormalities are:
A
- Aneuploidy
- Structural
4
Q
Enumerate the type of chromosomal mutations (variation in chromosome structure)
A
- Deletion
- Duplication
- Inversion
- Translocation
5
Q
What are the four types of aneuploidy?
A
- Monosomic
- Trisomic
- Nullisomic
- Tetrasomic
6
Q
These mutations alter chromosome structure in which overall chromosome number is unaffected, but large pieces of chromosomes ‘move’.
A
Chromosome Rearrangements
7
Q
One of more individual chromosome pair has its number altered.
A
Aneuploidy
8
Q
What are the diseases caused by aneuploidy condition?
A
Down syndrome
Klinefelter’s
Turner’s
9
Q
One of more complete chromosome sets are added.
A
Polyploidy
10
Q
Chromosomal aberrations are most often caused by errors during?
A
Cell division
11
Q
Aneuploidy may result when an error occurs during?
A
Meiosis
12
Q
TRUE or FALSE
If a sex cell affected by nondisjunction undergoes
fertilization, the resulting offspring will have inherited one more or one less chromosome and may develop a chromosomal disorder.
A
True
13
Q
This is defined as a pair of homologous chromosomes has failed to separate or segregate at anaphase so that both chromosomes of the pair pass to the same daughter cell.
A
Nondisjunction
14
Q
TRUE or FALSE
Nondisjunction occurs most commonly in meiosis, but it may also occur in mitosis to produce a mosaic individual.
A
TRUE
15
Q
TRUE or FALSE
Structural chromosomal aberrations can result in an polyploidy.
A
FALSE
Aneuploidy dapat.
16
Q
Chromosomal disorders are caused by ___ when there are two or more different cell lines in one person.
A
Mosaicism
17
Q
International standard for human chromosome nomenclature, which includes:
- Band names
- Symbols
- Abbreviated terms
A
International System for Human Cytogenomic Nomenclature (ISCN)
18
Q
The abbreviation minus sign (-) means?
A
Deletion
19
Q
The abbreviation “del” means?
A
Deletion of parts of a chromosome
20
Q
It is a chromosomal mutation that results in the doubling of a segment of a chromosome.
A
Duplication
21
Q
Enumerate the forms of duplication.
A
- Tandem duplication
- Reverse duplication
- Terminal tandem duplication
- Misplace duplication [wala sa ppt pero sinabi ni sir ian]
22
Q
This causes Charcot-Marie-Tooth disease type 1A.
A
dup(17p12)
23
Q
This genetic code is example of what form of duplication?
ABCD*EFEFGH
A
Tandem duplication
24
Q
This genetic code is example of what form of duplication?
ABCD*FEEFGH
A
Reverse duplication
25
This genetic code is example of what form of duplication?
ABEFCD*EFGH
Displaced duplication
26
TRUE or FALSE
Due to **unbalanced gene dosage**, duplications may have significant effect on an individual's phenotype.
TRUE
27
TRUE or FALSE
Problems arise during **prophase I of meiosi**s and synapsis when **homozygous** for duplication. Meaning, one duplicated region must **loop out** to allow synapsis to occur.
FALSE
Heterozygous dapat.
28
TRUE or FALSE
When a gene duplicates, the new duplicate gene can be free to mutate and evolve, while the original gene continues carrying on normal functions
TRUE
29
What are the examples of large-scale chromosomal duplications?
- Pallister Killian Syndrome
- Potocki-Lupski Syndrome
- Fragile X Syndrome
30
This is the result of extra #12 chromosome material.
Pallister Killian Syndrome
31
What are the phenotypes of Pallister Killian Syndrome?
- Poor muscle tone
- "Coarse" facial features
- Prominent forehead
- Very thin upper lip
- Ticker lower lip
- Short nose
32
Potocki-Lupski Syndrome is a chromosomal duplication condition that results from having an extra copy of small piece of chromosome number?
Chromosome 17
33
Potocki-Lupski Syndrome is also known as?
17p11.2 duplication syndrome
34
What are the phenotypes of Potocki-Lupski Syndrome?
- Weak muscle tone (hypotonia)
- Swallowing difficulties (dysphagia)
- Babies do not grow and gain weight at expected rate (failure to thrive)
35
This syndrome is resulted from multiple duplications of a CGG segment (trinucleotide) in the 5' untranslated region of the FMR1 gene on the X chromosome (Xq27).
Fragile X Syndrome
36
What are the four forms of Fragile X syndrome?
1. 6-40 repetitions = weak form
2. 41-60 repetitions = middle form
3. 61-200 repetitions = strong form
4. >200 repetitions = full mutations, influencing the phenotype
37
TRUE or FALSE
Fragile X syndrome is an X-linked mutation that affects men.
TRUE
38
It involved the loss of a segment of chromosome.
Deletion
39
Deletion is tested molecularly through?
CGH (Comparative Genomic Hybridization)
40
Enumerate the 3 types of deletion.
1. Terminal deletion
2. Intercalary/Interstitial deletion
3. Microdeletion
41
Type of deletion that occurs towards the end of a chromosome.
Terminal deletion
42
Type of deletion that occurs from the interior of a chromosome.
Intercalary/interstitial deletion
43
A relatively small amount of deletion (up to 5Mb that could include a dozen genes). A large amount of deletion would result in immediate abortion (miscarriage).
Microdeletion
44
TRUE or FALSE
If the deletion is large enough, it can be detected in a karyotype as a shortened chromosome.
omsim
45
TRUE or FALSE
If the deleted region includes the centromere, the mutated chromosome will not segregate during mitosis or meiosis.
TRUE
46
TRUE or FALSE
Recessive alleles express more readily when there are deletions.
TRUE
47
TRUE or FALSE
Most deletions are **not detrimental** when an individual is homozygous for the deletion.
FALSE
It is highly detrimental.
48
Deletion of a number of pairs that is not evenly divisible by three will lead to a f_____ m_____, causing all of the codons occurring after the deletion to be read incorrectly during translation, producing a severely altered and potentially nonfunctional protein.
Frameshift mutations
49
Deletion in what encoding gene causes spinal muscular atrophy?
SMN-encoding gene
50
Deletions are responsible for an array of genetic disorders, including?
- 2/3 cases of Duchenne muscular dystrophy
- 2/3 cases of Cystic fibrosis (caused by ΔF508)
51
Chronic lymphocytic leukemia (CLL) is the most common leukemia affecting adults. This most common alteration is the deletion in the long arm of what chromosome number and region?
Long arm of chromosome 13, at position 14 (13q14) region.
52
Identify the deletion syndrome based on the given phenotypes:
Infants have catlike cry, some facial anomalies, severe mental retardation.
Cri du chat syndrome (5p-)
53
Identify the deletion syndrome based on the given phenotypes:
Kidney tumors, genital and urinary tract abnormalities
Wilms tumor (11q-)
54
Identify the deletion syndrome based on the given phenotypes:
Cancer of the eye, increased risk of other cancers
Retinoblastoma (13q-)
55
Identify the deletion syndrome based on the given phenotypes:
Infants: weak slow growth
Adults: obesity, compulsive eating (Type II diabetes)
Prader-Willi Syndrome (15q-)
56
What gene is loss in the Angelman Syndrome that is located on the segment of chromosome 15 and connected with albinism?
OCA2 gene
57
TRUE or FALSE
People with Angelman Syndrome often smile and laugh frequently and have a happy and excitable personalities.
TRUE
58
TRUE or FALSE
Angelman Syndrome is curable.
FALSE.
59
It is a chromosomal mutation that results when a segment of a chromosome is excised and then reintegrated in an orientation 180 degrees from the original orientation.
Inversion
60
This form of inversion includes the centromere.
Pericentric Inversion
61
This form of inversion does not include the centromere.
Paracentric Inversion
62
TRUE or FALSE
It is believed that inversions played an active role in the evolution of humans.
TRUE
63
TRUE or FALSE
Individuals heterozygous for inversion do require some super-funky loops in order to allow synapsis in meiosis.
TRUE
63
TRUE or FALSE
If an **inversion breaks a gene in half**, moving half of that gene to another part of the chromosome, that gene will be **rendered inactive.**
FALSE
Active.
63
This is the change in position of chromosome segments and the gene sequences they contain, where no gain or loss is occurred in the genetic material.
Translocation
64
This kind of translocation changes in position of a chromosome segment within the same chromosome, no duplication occurs.
Intrachromosomal
65
This kind of translocation transfers a chromosome segment from one chromosome into a nonhomologous chromosome. It involves the movement of a chromosomal segment from one location in the chromosome to another.
Interchromosomal
66
This ISCN is used to denote a translocation between chromosome A and chromosome B.
t(A;B)(p1;q2)
67
TRUE or FALSE
Translocations can also result in position effects where moved genes are now regulated differently.
TRUE
68
This genetic code is an example of what type of interchromosomal translocation?
ABCD⚫EFGH
STUV⚫WXYZ
AB⚫EFGH
STUV⚫WCDXYZ
Nonreciprocal Translocation
69
This genetic code is an example of what type of interchromosomal translocation?
ABCD⚫EFGH
AXYB⚫EFGH
STUV⚫WCDZ
Reciprocal Translocation
70
The short arms and/or the long arms of the same chromosome join at the centromere that creates two copies of a large genetic region and shows characteristic mirror image appearance of banding patterns extending in both directions from centromere. What is this?
Isochromosomes
71
A special cases of joining at the centromere, occur between chromosomes that have tiny, short arms (acrocentrics).
Robertsonian Translocation
72
TRUE or FALSE
In Robertsonian Translocation, there's no obvious lost in genetic information because the short arms contain repeated rRNA genes.
TRUE
73
Enumerate the human tumors and conditions caused by translocation.
- Chronic Myelogenous Leukemia
- Burkitt's Lymphoma
74
Chronic Myelogenous Leukemia is a reciprocal translocation between what arm and chromosome?
Long arm of chromosome 22 and 9
75
This type of translocation is common in Africa, a virus-induced tumor, and where malignant B cells secrete antibodies.
Burkitt's Lymphoma
76
Burkitt's Lymphoma is the reciprocal translocation of what chromosomes?
Chromosome 8 and 14
BurkITT - it (eight) ehehhe
77
Burkitt's Lymphoma is the activation of what proto-oncogene?
c-myc
78
This is where the organism or cell has one or exact multiple of complete set(s) of chromosomes.
Euploidy
79
In euploidy, chromosome mutations may occur which results in?
1. Variation in the number of **individual chromosomes**
2. Variation in **complete sets** of chromosomes
80
This is where one or several chromosomes are lost from or added to the normal set of chromosomes, also results from nondisjunction where the irregular distribution of sister chromatids during mitosis or of homologous chromosomes during meiosis.
Aneuploidy
81
TRUE or FALSE
It is **not possible** for an individual to have **multiple instances of aneuploidy** and still have a **normal chromosome number**.
FALSE
Possible.
82
This aneuploidy disorder occurs when there are three copies of chromosome 21.
Down Syndrome
83
Identify the aneuploidy disorder based on the following phenotypic features:
- Wide skull that is flat at the back
- Eyelids have an epicanthic fold
- Iris contains spots
- Tongue is furrowed & protruding
- Physical growth
- Behavior and mental development are retarded
- Some have congenital heart defects
Down Syndrome
84
This aneuploidy disorder contains three copies of chromosome 13.
Patau Syndrome
paTau
Thirteen
85
Identify the aneuploidy disorder based on the following phenotypic features:
- Cleft lip and palate
- Small eyes
- Polydactyly (extra fingers and toes)
- Mental and developmental retardation
- Severe malformations of the brain and nervous system
Patau Syndrome
86
What are the phenotypic features of Edward Syndrome?
- Multiple congenital malformations affecting almost every organ system
- Clenched fists
- Elongated skull
- Low-set malformed ears
- Mental and developmental retardation
87
Edward Syndrome affected infants that are (male, female).
Female
88
Why is the maternal age considered as the leasing risk factor for autosomal trisomy?
1. The integrity of **primary oocytes decreases** as the woman age.
2. **Maternal selection** becomes **less effective.**
89
This sex chromosome disorder is the monosomy for the X chromosome that only affects females.
Turner Syndrome (45, X)
90
What are the phenotypic features of Turner Syndrome?
- Short and wide-chested
- Extra folds of skin on the neck (webbed neck)
- Underdeveloped breasts and rudimentary ovaries
- Absence of Barr body
- Color blindness
- Narrowing of aorta
91
This sex chromosome disorder is most common in males, where its phenotypic features do not develop until puberty.
Klinefelter Syndrome (47, XXY)
92
What are the other forms of Klinefelter Syndrome?
- 48, XXYY
- 48, XXXY
- 49, XXXXY
93
This sex chromosome disorder has a high testosterone levels that affects males, where early studies associate violent criminal behavior with the presence of extra Y chromosome.
XYY/Jacob Syndrome (47, XYY)
94
TRUE or FALSE
X chromosome is essential for survival. It emphasizes the role of X chromosome in the normal development.
TRUE
95
TRUE or FALSE
Addition of extra copies of either sex chromosome interferes with normal development and causes both physical and mental problems.
TRUE
96
This type of polyploidy arises as a result of mitotic or meiotic errors.
Autopolyploidy
97
When polyploidy represents a hybridization between species, with chromosome sets coming from different sets. It is sterile in the sense that they cannot cross-fertilize, but since plants are often self-fertilizing, these polyploids can often perpetrate themselves in this way. What is this?
Allopolyploidy
98
Most common form of polyploidy , where triploid infants have only limited survival, and most die within a month.
Triploidy
99
What are the three forms of triploidy?
o 69, XXY
o 69, XXX
o 69, XYY
100
It is a hybrid gene formed from two previously independent genes.
Fusion gene
101
Fusion gene occur as a result of?
1. Translocation
2. Interstitial deletion
3. Chromosome inversion
102
Patau Syndrome occurs in _ in 15,000 live births.
1
103
This trisomy occurs on 1 in 25,000 to 50,000 live births (very rare).
Trisomy 8
104
Chronic myelogenous leukemia is the transition of what fusion genes?
c-abl within the bcr region
105
This human tumor caused by translocation results to uncontrolled replication of myeloblasts.
Chronic myelogenous leukemia
106
Identify what type of aneuploidy:
- both members of a homologous pair are lost; involves a loss of one homologous pair
- from 46 chromosomes to 44
Nullisomy
107
Identify what type of aneuploidy:
- involves a loss of a single chromosome
- 2N-1
Monosomy
108
Identify what type of aneuploidy:
- One extra chromosome is gained
- 2N+1
Trisomy
109
Identify what type of aneuploidy:
- Involves an extra chromosome pair
- 2N+2
Tetrasomy
110
The average survival of Edward Syndrome lasts from ___ to ___ months.
2-4 months
111
TRUE or FALSE
Since males are constantly producing new gametes, and females’ gametes are ‘prepared’ during development, meiotic problems are observed in females as their age increases.
TRUE
112
This disomy ‘translates’ into “getting two chromosomes from one parent”
Uniparental Disomy
113
Polyploidy is common in plants and the major driving force behind?
Plant speciation
