Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Cytogenetics > Cytogenetics > Flashcards

Cytogenetics Flashcards

(61 cards)

Start Studying
1
Q

What is the definition of mosaicism?

A

variation of at least 2 cell lines

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

Is Mosaicism acquired or inherited?

A

Acquired, it can not be inherited

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

What aneuploidy is not viable?

A

Many Monosomies with an exception of 45X is viable.

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

What is 47XXY?

A

Klinefelter syndrome

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

what is genetic disease is caused by trisomy 21?

A

Down syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are clinical features of down syndrome

A

Multiple System Defects in in the heart, brain and lung,

Usually Infertile

Developmental delay

(M.U.D)

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

What genetic disease is caused by Trisomy 13?

A

Patau Syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are clinical features of Patau syndrome?

A

Cleft lip and paltate

“Punched out scalp”

Polydactyly

Rocket-bottom feet

(C.P.P.R)

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

What genetic disease is caused by Trisomy 18?

A

Edwards Syndrome

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

What are the the clinical features of Edwards syndrome?

A

Hypoplasia of muscles

Polydactly

Cross Fingers

Rocket-bottom feet

( H. PCR)

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

What does it mean by “females are mosaics for heterozygous traits”?

A

Means that some portion of their cells express one trait and some cells have a different traits.

(Basically due to x-inactivation, women can have heterozygous traits produced from their maternal X and paternal X.)

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

what is a disomy?

A

is presence of 2 chromosomes

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

what is isodisomy?

A

is 2 chromosomes from the same source

ie. duplication of 1 chromsome

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

what is Heterodisomy?

A

is 2 different chromosomes

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

what is a diploid?

A

presence of 2 copies of each unique chromosome

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

what is a haploid?

A

one copy of each unique chromosome

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

What is XXX female features?

A
  • 1 /1000 female births
  • Tall stature
  • due to meiosis I maternal error
  • usually Phenotypically normal
  • normal fertility
  • normal intelligence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is features of an XYY male?

A

1/1000 births

  • Tall stature
  • due to paternal meiosis I error
  • phenotypically normal
  • normal fertility
  • normal intelligence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the genetic disease for karyotype 47, XXY?

A

Klinefelter Syndrome

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

clinical features of Klinefelters Syndrome?

A
  • 1/1000 births
  • Tall stature

50% due to meiosis I error in dad

  • Infertility
  • female characteristics may develop
  • learning deficit possible

(L.I.F.T 50)

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

What genetic disease is associated with karyotype 45X?

A

Turner Syndrome

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

What are some clinical features of Turner Syndrome?

A

1/5000 live female births

  • Short Stature
  • Webbed neck in utero
  • usually Infertile
  • 10% are mosaics (with 45X/XX and 45XY
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

If you end up with the 45X/XY what can happen for male and female phenotype?

A
  • If you show male phenotype, you are normal
  • If you show female phenotype, then you need to surgically remove your gonads or be at risk of gonadoblastoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the clinical features of XY female?

A

1/20000 live births

-Phenotypically normal female with testes

Infertility

Androgen Insensitivity

(P.I.A.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the clinical features of XX male?
1/20000 live births X-Y recombination near pseudoautosomal region Usually nomal, possible Klinefelter phenotype Reciprocal translocation (TDF/SRY is replaces by Xp material which is transmitted to child, resulting in Turner female phenotype
26
what is a **balanced** structural abnomality?
when all material is present but is just re-arranged
27
What is **unbalanced** structural abnormalities?
this is when material is missing or duplicated
28
What is a contiguous genome?
associated genomes on the same locus but are unrelated to eachother ie. VCFS and William Beuren Syndome
29
What are the clinical features of VCFS?
Short Stature Facial Anomalies, Cardiac anomalies Cleft palate and lip Learning disability Weak immune system Hypotonia
30
What are the clinical features of William Beuren Syndrome?
Outgoing and friendly Usually low IQ Thickening of skin Renal Anomalies Excellent music skills, suck at math Stellate Iris Skeleltal muscle and joint limitations Blue sclera Supravalvular aortic Stenosis (O.U.T. R.E.S.t B.S)
31
What is alternate segregation?
- Chromosome 1 segregrate together and chromosome 2 segregate together forming balanced gametes - No rearrangement and balanced translocation
32
What is adjacent 1 segregation?
When chromosome one segregate and the 2s segregate together (centromeres move to opposite poles), leading to unbalanced translocation. -will have duplications and deletions of gene regions.
33
what is adjacent 2 segregation?
Same as adjacent 1 but instead centromeres move to the same pole (normally they are suppose to move to opposite poles)
34
What is 3:1 segregation?
This is a segregation in which you end up with 3 chromosome in one cell and 1 chromosome in another. -Products are highly unbalanced and unlikely to be viable
35
Balanced translocations important features are?
- they can be de novo - Translocations can be inherited - Carriers are usually phenotypically normal - though chromosomal material is there, there is rearrangement
36
What is the significance of a balanced translocation for an individual?
- poses an increased risk of another pregnancy having a unbalanced chromosome complement - increased risk of abnormal live born
37
FISH (fluorescence In-Situ Hydbridization) How does it work?
Using a fluorescent colored probe allows binding to the denatured DNA before it re-aneals
38
Benefits of FISH
- allows you to detect chromosomal re-arrangements, duplications, and deletions - easy to score using colors - Does not require metaphase cells - accurate
39
Disadvantages of FISH
- your probe is locus and chromosome specific ( this means you have to already need to have an idea of what you are looking for) - probes do not cover the entire abnormality - a very small deletion or duplication may be to small for probe to hybridize - variant duplication or deletion may not even be detected if it is outside of the boundary of the abnormality
40
When do I use FISH?
when you can't screen all your chromosomes If you think you know the disease To maximize your results If the karyotype analysis has given you chromosomes (use that info)
41
What is Identity by Descent?
aka consanguity - have an increased risk of autosomal recessive traits - have increased risk of expression of autosomal recessive traits
42
What is Microarray benefits?
- useful for identifying CNV 10kb or larger - identifies unbalanced translocations - detects AOH (absence of heterozygosity, ROH (region of homozygosity), IBD (identity by descent) - detects mosacism
43
Disadvantages to microarrays
- can not detect balanced translocations - or CNV's less than 10kb
44
What is NGS sequencing
-technology which performs a genome-wide scan to detect for mutations associated with patients medical concerns
45
Strengths of NGS sequencing
- Targeted of Genome wide screen - detection of very small abnormalities (\<21bp)
46
Weaknesses of NGS sequencing
- Time for reporting - cost - you get alot of data that has no clinical correlation - difficulty detecting mosacism, translocations, and IBD
47
If I wanted to detect balanced translocations what cytogenetic tools would I use?
FISH, NGS sequencing (more expensive)
48
What tests would I use if I wanted to detect unbalanced translocations?
Microarray, karotype analysis,
49
If I wanted to do some genomic screening what tests would I use?
Microarray and NGS sequencing
50
What molecular tool would I use if I was involved in a case of Uniparental disomy?
Microarray or molecular analysis
51
what is X-inactivation?
- done in females to provide gene dosage compensation - heavy methylation of one of female X chromosomes occurs turning it off. - this is what allows for mosaics with heterozygous traits. (some sex cells with one trait and some other cells with another trait)
52
Genomic Imprinting
chromosome methylation patterns specific to parents, that are passed from each of them to the zygote.
53
what does Male vs. Female effect in Imprinting mean?
The male imprinted chromosome (chromosome with methylation patterns) when affected with disease causing mutations or translocations, it can give different epigenetic disease to child than female's imprinted chromosome affected by mutation and deletion. ie. Prader Wili vs. Angelman Syndrome (caused by same mutation, but different genomic imprint)
54
what is Uniparental disomy
inheritance of a pair of chromosomes from 1 parent (in contrast to the normal being one from mom and one from dad) -usually can not be detected using karyotype, must use molecular analysis tech.
55
what is uniparental isodisomy?
duplication of the same chromosome from one parent
56
what is uniparental heterodisomy
different 2 chromosomes from the same parent.
57
What is biparental heterodisomy?
two different chromosomes from different parent.
58
How can you get Prader Wili Syndrome?
1) deletion in the paternal impint being passed on with maternal imprint 2) dad's meiosis error (not re-imprinting his paternal chromosome causing his maternal imprint to be passed on along with mom's paternal imprint (2 maternal imprints)- results in only functional maternal alleles
59
Clinical features of Prader Wili Syndrome
small, hypotonia, and gain weight easily, -dont have satiety pathways so never get full
60
clinical features of Angelman Syndrome
- severly mentally retarded - friendly but can't hold on normal conversations - their discourse (spoken communication) often punctuated with inappropriate laughter.
61

Cytogenetics (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions