Molecular Cytogenetics

Question 1

1. Recognize two of the most common leukemia translocations - one in chronic myeloid leukemia (CML) and one in acute pro-myeloid leukemia (APMO/L), and discuss the importance of these chromosomal findings that lead to biologically-based, targeted therapy (it’s all in the genes!).

Answer 1

CML: t(9;22) is diagnostic for CML which can be tyrosine kinase inhibitors
APML: (t15;17) is diagnostic for APML, can be treated with retinoic acid

Question 2

2. Describe the common cytogenetic findings in childhood B-cell leukemia and how the cytogenetic findings influence patient prognosis.

Answer 2

High hyper-diplody revealed by chromosome and FISH analyses

Question 3

3. Delineate types of fluorescence in situ hybridization (FISH) probes and how they complement standard cytogenetic analysis, particularly in hematologic.

Answer 3

used for initial differential diagnosis, means to monitor treatment or disease progression. below examples used for specific diseases, primary hematologic malignancies, and solid tumors (eg breast cancer, brain cancer, lung cancer, selected sarcomas)

centromere: name: cen; used for: enumeration: leukemias; example: Cen 4, 8, 10, 17

locus specific: name: LSI, used for: deletion-leukemias; p53

fusion/dual fusion: name: F, DF; used for: translocation: leukemias; example: BCR, ABL, PML, RARA

Question 4

4. Explain the roles of chromosomal microarray (CMA) analysis in aiding certain 0020 genetic diagnoses and why CMA testing can detect genomic deletions or duplications, but not translocations.

Answer 4

used for children with developmental delays

Question 5

5. Recognize laboratory test algorithm for children who present with learning disorders, developmental delays, autism, dysmorphic features, and/or failure to thrive.

Answer 5

a