12.1 Genetic Testing Old&New Flashcards
1
Q
how to test for chromosomal disorders?
A
Karyotype FISH chrimosome microarray (CMA)
2
Q
how to test for single gene disorders
A
- triplet repeat disorders
- sanger sequencing
- next gen’'’sequencing
3
Q
karyotyping can only detect changes in genes of what size
A
5-10 megabases
4
Q
how to detect 22q11 deletion?
A
FISH
5
Q
22q11 features?
A
subtle facial similarities
congenital heart disease
cleft palate
6
Q
FISH limitations?
A
deletion size is inferred, not measured
7
Q
if you want to order FISH?
A
talk to lab first
need to specify diagnosis in question
8
Q
what is the “usual’’ DNA test we do
A
chromosome microarray (CMA)
9
Q
use the CMA test if you are inquiring about?
A
- Intellectual disability
- multiple congenital anomalies
- dysmorphism
- austistic spectrum
- psychiatric
- epilepsy phenotypes
10
Q
how to appraoch a VOUS? (variants of unknown significance)
A
- in 5-7% of all CMA tests
- NOT a dx
- if inherited from clinically normal parents, likely benign
11
Q
What to do with VOUS?
A
Test the parents,
review phenotype,
Do they have the same copy variations?
12
Q
What does CMA NOT detect?
A
- reciprocal trans locations
- repeat expansions
- not a gene sequencing
