Genetic Testing

Question 1

aneuploidy

Answer 1

entire missing or extra chromosome

ex: trisomy

Question 2

trisomy 21

Answer 2

down syndrome

Question 3

What genetic tests detect aneuploidy?

Answer 3

karyotype and FISH testing

Question 4

microdeletion / microduplication

Answer 4

extra or missing chromosome regions of varying size

ex: DiGeorge

Question 5

What tests can you use to detect microdeletion / microduplication?

Answer 5

microarray (possibly FISH)

Question 6

What tests detect translocations and inversions?

Answer 6

karyotype or FISH

Question 7

Balance translocation / inversions

Answer 7

reciprocal exchange (nothing lost or gaineed)

usually not pathogenic

Question 8

Unbalanced translocation / inversions

Answer 8

typically pathogenic

Question 9

Lynch syndrome is an example of …

Answer 9

single gene mutation

Question 10

What is a common example of epigenetics?

Answer 10

Prader-Willi Angelman syndrome

Question 11

What tests work for epigenetics?

Answer 11

methylation testing

Question 12

karyotype

Answer 12

looks at big picture of chromosomes

large structural differences

Question 13

What indicates karyotype testing?

Answer 13

Fhx of trisomy

ambiguous genitalia

multiple miscarriages

Question 14

When do you do karyotype testing?

Answer 14

during the prenatal period

Question 15

FISH testing

Answer 15

fluorescent probe tests for specific DNA sequences

Question 16

SNP microarray

Answer 16

can detect small missing or extra pieces of chromosomes

Question 17

Limitation of SNP microarray

Answer 17

cannot detect single gene variation

cannot detect large structural rearrangements

Question 18

When do you use SNP microarray?

Answer 18

during the prenatal period

Question 19

Panel testing

Answer 19

can test several genes at once

Question 20

When do you do a genetic panel?

Answer 20

condition with possible known genetic mutations, similar phenotypes

Question 21

When do you use whole exome / genome testing?

Answer 21

when other tests were negative

Question 22

Limitation of whole genome testing?

Answer 22

doesn’t sequence introns + mitochondrial DNA

can’t detect large structural rearrangements

Question 23

Methylation disadvantage

Answer 23

gives no information about the genetic code

Question 24

Cell-free DNA

Answer 24

looks for DNA in blood

just a SCREENING, need to send more tests after

Question 25

What can cell-free DNA be used for?

Answer 25

prenatal screening

somatic tumor