Question
Which of the following is used in diagnosing aneuploidy?
- FISH
- Cytogenetics
- Sanger sequencing
- PCR
| A. |
1, 2
|
| B. |
1, 2, 3
|
| C. |
2, 3
|
| D. |
1, 2, 3, 4
|
Show Answer
|
Correct Answer » A
Explanation
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|
- Aneuploidy refers to gain or loss of whole chromosomes (e.g., Trisomy 21, Monosomy X).
- Detection requires methods that can assess chromosome number or copy number.
- FISH (Fluorescence in situ hybridization)
- Uses fluorescent probes targeting specific chromosomes
- Counts chromosome copies in interphase or metaphase cells
- Rapid method for detecting common aneuploidies
- Cytogenetics (Karyotyping)
- Gold standard method
- Direct visualization of entire chromosome set
- Detects both numerical and structural abnormalities
Explanation why other options are incorrect
- Sanger sequencing
- Detects point mutations or small nucleotide changes
- Cannot detect whole chromosome gain or loss
- The uploaded content incorrectly suggests a role, but sequencing is not used for aneuploidy detection
- PCR (Polymerase chain reaction)
- Standard PCR amplifies DNA sequences
- Does not measure chromosome number
- Only specialized form (QF-PCR) is used for aneuploidy, not conventional PCR
