t(9;22)(q34;q11)

The t(9;22)(q34;q11) translocation occurs in chronic myeloid leukemia (CML) and adult B-cell acute lymphoblastic leukemia (ALL), leading to fusion of BCR to ABL1 and constitutive activation of ABL1 tyrosine kinase activity.

The main BCR-ABL1 breakpoints result in P190 BCR-ABL1 or P210 BCR-ABL1 fusion proteins. The latter is found in almost all cases of CML and in one third of the cases of t(9;22)-positive adult B-ALL. P190 BCR-ABL1 is found in the remaining two thirds of t(9;22)-positive adult B-ALL cases but only exceptionally in CML.

ABL1 at 9q34 and BCR at 22q11

Tumors

 chronic myelogenous leukemia (CML) ( 100%) (AGCOH)

 acute lymphoblastic leukemias (ALLs) (AGCOH)

 acute non-lymphoblastic leukemias (ANLLs) (3%) (AGCOH)

• childhood non-acute lymphoblastic leukemia (childhood ANLLs) (1%) (AGCOH)
• t(9;22)(q34;q11) associated with t(10;11)(p13;q14) in acute monocytic leukemia (16518848)

Constitutive activation of tyrosine kinases by mutations or fusions as BCR-ABL1 could be associated with deregulation of transcription factors central to myeloid differentiation (HOXA9 secondary to PICALM-MLLT10).

Associatiuons

 overexpression of HOXA9 (16518848)

• HOXA9 is a gene essential to myeloid differentiation that is expressed in PICALM-MLLT10 and MLL-rearranged acute leukemias. (16518848)

See also

 Oncobase
 leukemia-associated translocations
 tumoral translocations