Cytogenetics

Question 1

? Markers found on 
Immature cells
T cells
B cells
Myeloid cells
Monocytes

Answer 1

Immature cells CD 34, 117, HLA DR
T cells CD 2,3, 4, 8
B cells CD 19, 20, 22
Myeloid cells CD 15, 33
Monocytes CD 11, 53

Question 2

?role of p53

Answer 2

“Guardian of the genome”
Nuclear Transcription factor that regulates cell cycle and apoptosis
Somatic mutations of p53 account for 50% of cancers!!!

Li-Fraumeni: germline mutation of p53 gene
(First hit = 85% lifetime cancer risk)
50% tumours

Question 3

? Gene linked to hered retinoblastoma

Answer 3

40%of all RB is hereditary
RB1 gene germline mutations
80% de novo
20% has fam hx

RB protein is a tumour suppressor
- Knudsons 2 hit hypo: germline mut the. Somatic mut
Both RB1 alleles mutated = tumour

Question 4

AML cytogenetics

Name 5 favourable mutations

Answer 4

T(15;17)
T(8:21) ETV6-RUNX-1
Inv 16

NPM1 favourable risk fx
CEBPA

Question 5

AML

Non favourable cytogenetics

Answer 5

Monosomy 7 (a/w NF) and 
FTL3-ITD adverse risk factor predicts relapse and consider transplant at first relapse

Question 6

ALL CYTOGENETICS

?better prognosis

Answer 6

t(12;21) TEL-AML1 fusion

Hyperdiploid

Question 7

ALL CYTOGENETICS ?bad prog

? Risk assignment now

Answer 7

t(9;22) BCR-ABL fusion
t(4;11) MLL-AF4 fusion 
Hypodiploid (10% D 15, non remission day 33
Positivity for MLL/AF4 or hypodiploidy
High risk by PCR-MRD response

Question 8

Acute ALL poor prog factors

Answer 8

Age 10 at dx
Male
Wcc >50 at dx
Immunophenotype pro-B or T cell
CNS disease
>1 X 10^9/L blood blasts after 7days induction with daily pred and a single dose intrathecal MTX on Rx day 1
>25% blasts in marrow day 7 and or day 15 or 5-25%blasts BM day 15
Remission status no response: >5%blasts BM after induction