Techniques of chromosome analysis Flashcards
Which of the following is used to analyse the whole genome?
1) G banding
2) FISH
3) MLPA
4) Next generation sequencing
5) Microarrays
6) QF-PCR or qPCR
The following are used to analyse the whole genome:
1) G banding
4) Next gen sequencing
5) Microarrays
The following methods are used for targeted testing:
2) FISH
3) MLPA
6) QF-PCR or qPCR
FISH is a molecular cytogenic technique used for targeted testing. What does FISH stand for?
Fluorescent in situ hybridisation
MLPA is a molecular cytogenic technique used for targeted testing.What does MLPA stand for
Multiplex ligation dependent probe amplification
What molecular cytogenic technique detects DNA material on slides using fluorescent dyes and UV light?
FISH
(flourescent in situ hybridisation)
detects DNA material on slides by using fluorescent dyes and UV light.
What are the different types of probes used in FISH.
- unique sequence
- centromeric
- paints
When can FISH be used?
1) Aneuploidy (abnormal numbers of chromosomes)
2) confirmation of G-banding test
3) confirmation of array CGH test
4) identifying specific abnormalities in cancer
5) copy number imbalance (repeats of dna)
What diseases can occur due to copy number imbalances?
Autism (congenital)
cancer (acquired)
What molecular cytogenetic methods are used to assess copy number?
1) FISH
2) MLPA
3) Microarray CGH
4) Next generation sequencing
5) QF-PCR / qPCR
(not G banding)
What does QF-PCR stand for? what is it?
Quantitative Flourescent polymerase chain reaction.
PCR amplification of short DNA sequences using fluorescent primers.
What is used to detect prenatal aneuploidy ?
QF-PCR
- DNA is extracted from the amniotic fluid / chorionic villi
- PCR amplification looking for aneuploidy of chromosomes 13, 18, 21, X and Y
trisomy 13
patau syndrome
patau syndrome
trisomy 13
Which analysis takes the shortest amount of time?
1) MLPA / QF-PCR = 10mins / 30mins/case
trisomy 18
edwards syndrome
edwards syndrome
trisomy 18
turners syndrome
45, X
45, X
turners syndrome
only affects females
In what situations would we ask for a blood cytogenetic study?
1) dysmorphic newborns
2) Gender assignment
3) Developmental problem
4) heart defect
5) reproductive problem
6) family studies
In a suspected case of down’s syndrome what are the 3 possible cytogenics?
1) free trisomy 21 (90-95%)
2) Translocation (robertsonian 2-5%)
3) Mosaic trisomy 21 (2-5%)
what is robertsonian translocation?
When the entire chromosomal arm is swapped
What is amniocentesis?
prenatal testing for chromosomal abnormalities, fetal infection, sex dertemination.
What is chorionic villus sampling?
Chorionic villus sampling (CVS) is a prenatal test in which a sample of chorionic villi is removed from the placenta for testing. The sample can be taken through the cervix (transcervical) or the abdominal wall (transabdominal).
what cytogenetic techniques are used to analyse amniotic fluid and chorionic villi?
QF-PCR
G-banded analysis
