Clinical Cytogenics

Question 0

What are chromosome microarray tests used for?

Answer 0

To help diagnose individuals with developmental delays including multiple congenital disorders, autism, and intellectual disability.

Question 1

Which cytogenetic processes are used to reveal common genetic aberrations such as Down syndrome, or the causes of leukemia and lymphoma?

Answer 1

Chromosome and FISH analyses.

Question 2

Five tissues used for cancer diagnostics in cytogenetic testing.

Answer 2

Bone marrow
Unstimulated blood
Lymph nodes
Solid tumors
CSF

Question 3

What are the relative prognoses of hyperploidy and hypoploidy in B-cell Acute Lymphocytic Leukemia?

Answer 3

Hypoploidy has a poor prognosis (likely loss of tumor suppressors)
Hyperploidy has a good prognosis (likely gain of tumor promoters)

Question 4

What can a FISH study determine?

Answer 4

FISH can determine the total number of specific chromosomes or identify translocations, depending on the type of probe used.

Question 5

Five types of FISH probes and their uses

Answer 5

Centromere - enumeration of chromosomes
Locus specific - find deletions or duplications
Dual fusion/fusion - find translocations
Break apart - translocation rearrangements
Whole chromosome paint - identifying markers, translocations