U5 CHROMOSOMAL ABERRATIONS: INVERSION TO TRANSLOCATION Flashcards
Chromosomal mutations that results when a segment of a chromosome is excised and then reintegrated in an orientation 180 from the original orientation.
Inversion
For chromosomes to be excised, there should be what?
Double stranded breaks
Involves the centromere
Pericentric inversion
Does not involve centromere
Paracentric inversion
Abbreviations: inv
Inversion
Inversion between Human Chromosome 4 and Chimpanzee Chromosome 4
Pericentric inversion
Scientific term of Chimpanzees
Pan troglodytes
Molecular technique in Inversions
FISH
Effect of moving half of the gene to another part of the chromosome
Inactivation
Shifting of parts in chromosome
Position Effect
T/F: Position effect can lead to cancer.
True
What does heterozygous individuals require in meiosis for synapsis?
super-funky loops
De novo mutations that caused Brenden’s extreme height
HMGA2
Inverted chromosome in Brenden’s extreme height
Chromosome 12
Change in position of chromosome segments and gene sequences
Translocation
T/F: Translocations can be seen on karyotypes especially with non reciprocal translocation.
True
Change in position of chromosome segment within the same chromosome
Intrachromosomal
Transfer of chromosome segment from one chromosome into a non homologous chromosome
Interchromosomal
Non reciprocal translocation or one-way
Intrachromosomal
Translocations are usually non homologous except for?
Intrachromosomal
Abbreviations: T
Translocation
Abbreviations: Second set of parentheses in translocations
Precise location (p and q arm, bands)
Translocations that are more common, DNA is exchanged in both directions
Reciprocal Translocations
Translocations can also result in?
Position effect
Translocations can cause linked or fused genes that cam ne passed together
Fusion genes
More common fusion genes
Oncogenes
What accompanies translocations?
Chromosome deletions
For one portion of the chromosome to be translocated, it must first be ____ by what?
lost, original chromosome
especially in non reciprocal
Fusion of 2 chromosomes that lost information regions
Robertsonian translocation
both genes lost majority of short arm then nagsama sa isang region
In genetic heterogeneity, this can be a cause of Down Syndrome
Robertsonian translocation
What human chromosome has the same banding patterns in chimpanzee, gorilla, and orangutan chromosomes?
Human Chromosome 2
What coding region is fused in human chromosome 2?
Hair and arms (daw)
Exchange of segments between two chromosomes
Reciprocal
Transfer of segment in one direction from one chromosome to another
Non-reciprocal
Short arms and/or long arms of same chromosome join at the centromere
Isochromosomes
Creates two copies of a large genetic region, show characteristic mirror image of banding patterns in both directions
Isochromosomes
This refers to when there are seen breaks at the end of linear chromosomes which fuses after loss of genetic material.
Ring Chromosome
Abbreviations: mar
unidentified marker
Abbreviations: r
Ring Chromosome
What does arrowheads indicate in ring chromosomes?
Breakpoints
Ring Chromosome 14
Epilepsy
Ring Chromosome 15
growth and speech delay, microcephaly
Ring Chromosome 18
growth delay, facial abnormalities
Ring Chromosome 22
Hypotonia
Ring Chromosome X
Turner Syndrome
2 causes of Turner Syndrome
- Monosomy X
- Ring Chromosome X
Special cases of joining chromosomes that have tiny short arms (acrocentrics)
Robertsonian Translocation
T/F: Robertsonian Translocation does not produce fusion genes that are oncogenic.
False
What does short arm contain?
repeated rRNA gene (meaning no obvious lost in genetic info in Robertsonian translocation)
Reciprocal translocation between q of chromosome 22 and 9
Chronic Myelogenous Leukemia (CML)
CML: What gene transitions in the bcr region?
c-abl
CML: In what region does the c-abl gene transition to?
bcr
CML: Gene for non apoptosis of baby granulocytes (specifically Neutrophils)
BCR-ABL gene
This results to uncontrolled replication of myeloblasts.
Chronic Myelogenous Leukemia (CML)
CML: The BCR-ABL fusion gene is also known as?
Philadelphia chromosome
Hybrid gene formed from two previously independent genes
Fusion gene
TEL-AML, t(12:21)
Acute Lymphocytic Leukemia (ALL)
AML1-ETO, t(8:21)
M2 Acute Myeloblastic Leukemia (AML)
Fusion gene in Acute Promyelocytic Leukemia (PML/APL)
PML-RARA
PML/APL: Region in Chromosome 15
PML
PML/APL: Region in Chromosome 17
RARA
TMPRSS2-ERG, deletion on Chromosome 21
Prostate Cancer
Specialized database of chromosomal aberrations and gene fusions in cancer
Mitelman Database of Chromosome Aberrations and Gene Fusions in Cancer
Mark of young myeloblasts that should not be seen in peripheral blood
larger nucleus than cytoplasm
Reciprocal translocation between Chromosome 8 and 14
Burkitt’s Lymphoma
Activation of c-myc gene (protoonco gene)
Burkitt’s Lymphoma
What is the most common virus that induces tumor in Burkitt’s Lymphoma?
Epstein-Barr Virus
Cause of infectious mononucleosis
Epstein-Barr Virus
Other name for Epstein-Barr Virus
Kissing Disease
One chromosome 21 shifted to Chromosome 14 that causes position effect which mimics extra information in Trisomy 21
Translocation Down Syndrome
Organism or cell has one or exact multiple of complete set(s) of chromosomes
Euploidy
Organisms that have the same exact complete sets of chromosomes
True ploids (???)
Monosomy is acceptable only in?
Sex Chromosomes
T/F: Nondisjunction only happens in Meiosis I.
False
it can happen both in Meiosis I and II
Both members of a homologous pair are lost. 2n-2
Nullisomy
Loss of single chromosome, 2n-1
Monosomy
Involves a single extra chromosome, 2n+1
Trisomy
Involves an extra chromosome pair, 2n+2
Tetrasomy
T/F: You can have two trisomy conditions in one individual.
True (aka Double Trisomic)
T/F: Aneuploidy drastically affects phenotype.
True
Mental retardation and characteristic physical alterations but many still has normal life expectancy
Trisomy 8
Why is Trisomy X, Tetrasomy X, and Pentasomy X still viable?
Formation of Barr Bodies (X Inactivation)
XYY Syndrome
Normal
XXY, XXYY, XXXY
Klinefelter Syndrome
Trisomy 21
Down Syndrome
Phenotypic features of Trisomy 21
epicanthic folds are lower than tips of ear, prone to leukemia, wide skull that is flat at the back, protruding tongue
Trisomy 13
Patau Syndrome
Phenotypic features of Patau
cleft lip and palate, small eyes, polydactyly (extra fingers and toes), developmental retardation
T/F: More smaller trisomy, more common
True
Trisomy 18
Edward Syndrome
Average survival time of Edwards Syndrome
2 to 4 months (connective tissue is affected)
Phenotypic features of Edward
low-set malformed ears, short neck, elongated skull
Leading risk factor for Trisomy
Maternal Age
ready na daw dapat lahat ng excess in puberty, paisa isang release ng egg
Integrity of primary oocytes _____ as women age.
decreases
Phenotypic features of Turner Syndrome
webbed neck, short and wide chested, under developed breasts, rudimentary ovaries (loss of 1 X dosage), color blindness (males)
T/F: Males are prone to de novo mutations because of constant gamete formation.
True
T/F: Phenotypic features develop early.
False
they do not develop until puberty
Phenotypic features of Klinefelter syndrome
poor sexual development, very low fertility
XYY Syndrome is also known as
Jacobs Syndrome
Phenotypic features of Jacobs Syndrome
above average height, suffered personality disorders, below intelligence levels
T/F: Jacobs Syndrome is associated with violent crime behavior.
True
T/F: Uniparental disomy starts as trisomy, in which the absence of chromosome from father is observed.
True
All sets of chromosomes are from single species
Autopolyploidy
Polyploidy represents a hybridization between species
Allopolyploidy
T/F: Most allopolyploids are sterile and cannot cross-fertilize.
True
