t(9;22)

• Philadelphia chromosome

• present in > 95% of patients with CML

• this results in part of the Abelson proto-oncogene being moved to the BCR gene on chromosome 22

• the resulting BCR-ABL gene codes for a fusion protein which has tyrosine kinase activity in excess of normal

• poor prognostic indicator in ALL

t(15;17)

• seen in acute promyelocytic leukaemia (M3)
• fusion of PML and RAR-alpha genes

t(8;14)

• seen in Burkitt's lymphoma
• MYC oncogene is translocated to an immunoglobulin gene

t(11;14)

• Mantle cell lymphoma
• deregulation of the cyclin D1 (BCL-1) gene