clinical cytogenetics Flashcards
clinical cytogenetics
- cancer cytogenetics
- -important for leukemia and lymphomas - chromosomal microarrays
- -used in dx or children with delays
Chromosome & FISH analyses can reveal ____________
can reveal common genetic aberrations, e.g., Down syndrome
Chromosome & FISH studies important in investigating ____________
causes of leukemia & lymphoma
____________ studies important in investigating causes of leukemia & lymphoma
Chromosome & FISH
Specimens For Cytogenetic Studies
• Bone Marrow
• Blood
– Unstimulated
– Constitutional
• Tissue
– Lymph node
– Solid tumor – POC
• Fluids – CNS
– Amniotic fluidFISH =
FISH = fluorescence in situ hybridization
In cases of pediatric B-cell acute lymphocytic leukemia (ALL)
FISH probe: centromere
name: cen
used for: enumeration
example: all panel, prenatal dx
FISH probe: locus specific
name: LIS
used for: deletion/duplication
example: p53, cancer
FISH probe: dual fusion, fusion:
name: DF, F
used for: translocation
example: BCR; ABL, PML:RARa (cancer)
FISH probe: break apart
name: BAP
used for: Translocation rearrangement
example: MLL (cancer)
FISH probe: Whole chromosome paint
name: WCP
used for: Identifying markers, translocations
example: WCP 1-22, X, Y (all studies)
Some rearrangements are cryptic by ______ and require ________
standard cytogenetics
require FISH interpretation
AML
acute myelogenous Leukemia
seen more frequently in adult
CML treatmeant with Imantinib mesylate(ST1 57, Gleevec)
- targeted, biological therapy specific for CML cells
- Molecular antagonist: binds at ATP binding site in abl tyrosine kinase and bcr/able tyrosine kinase
- Inhibits cell proliferation and apoptosis
Chromosomal Microarry (CMA)
- Target DNA on slide (chip) is single- stranded oligomers
- CMA detects gains and losses ONLY “ not balanced rearrangements
- Limited ability to detect mosaicism “ (15-20%)
two most important leukemia translocation
- acute promyeloid leukemia
2. chronic myelogenous leikemia
acute pro myeloid leukemia is a _____
15/17 translocation
acute pro myeloid leukemia can be treated with
retinoid acid because mutated fusion of retioic receptor with PML gene does not allow for myeloid cells to differentiate and thus acid pushes it down a certain path
chronic myelogenous leukemia is a ____
9/22 translocation
chronic myelogenous leukemia treated with
gleevec (tyrosine kinase inhibitor)
which treats the out of control tyrosine kinase bcr/abl
high hyper diploid
over 50 chrome good prognosis
low hypoploidy
bad prognosis
cen used for
leukemia
centromere
lsi used for
deletions in leukemia
locus specific
