Translocations/Cytogenetics

Question 1

t(15;17)

Answer 1

Acute promyelocytic leukemia (APL)

Produces PML-RAR fusion gene –> retinoic acid important for myeloid maturation; disruption of receptor produces maturation arrest at promyelocyte stage

Question 2

AML with recurrent cytogenetic abnormalities

Favorable prognosis

Answer 2

t(8;12)
inv(16)
t(15;17)

Question 3

AML with recurrent cytogenetic abnormalities

Intermediate/unfavorable prognosis

Answer 3

11q23 (MLL) rearrangements

Question 4

t (12;21)

t(9;22)

Answer 4

B-ALL cytogenetic variants
t(12;21) –> good, kids
t(9,22) –> bad, adults

Question 5

t(9;22)

Answer 5

CML

BCR-ABL fusion gene produces protein with tyrosine kinase activity [treatment = imatinib]

Question 6

JAK2 mutations in nearly all cases

Answer 6

PV

Question 7

JAK2 mutations in 50% of cases

Answer 7

PMF (primary myelofibrosis)

ET

Question 8

-5 or del5q, +8, -7 or del7q

Answer 8

MDS

Question 9

BRAF mutations

Answer 9

Langerhans cell histiocytosis

Question 10

Defects in perforin gene

Answer 10

Primary (genetic) LH (Lymphohistiocytosis)

Question 11

Deletion 13q

Mutated IgHV

Answer 11

CLL/SLL – good prognosis

Question 12

Trisomy 12

Answer 12

CLL/SLL – intermed prognosis

Question 13

Deletion 11q
Deletion 17p (p53)
Unmutated IgHV
CD38/Zap-70 expression

Answer 13

CLL/SLL – bad prognosis

Question 14

t(8;14) most common

t(2;8)
t(8;22) are also possible

Answer 14

Burkitt lymphoma

c-myc (TF) & IgH fusion

Question 15

t(11;18)

Answer 15

Most common abnormality in gastric MALTomas (extranodal marginal zone lymphoma)
Creates MALT2-IAP2 fusion gene

Question 16

t(14;18)

Less common – BCL6 rearrangement

Answer 16

Follicular lymphoma

Creates BCL2-IgH fusion gene

Question 17

t(11;14)

Answer 17

Mantle Cell lymphoma

Creates cyclin D1-IgH fusion gene

Question 18

Rearrangements of ALK gene (tyrosine kinase receptor)

t(2;5)

Answer 18

Anaplastic large-cell lymphoma