BOF: Malignant (Leukaemia/Paediatrics)

Which of the following cytogenetic abnormalities is most common in infant (<1 year) Acute Lymphoblastic Leukaemia?

a) t(1;19)

b) t(4;11)

c) t(9;22)

d) t(12;21)

e) t(14;18)

Answer:

b) t(4;11)

Explanation

Translocations involving the 11q23 region that includes the MLL gene are well recognised in ALL, and also in AML. The most common translocation (70%) in infants is t(4;11), and conveys a poor prognosis in this age group. All the other translocations are recognised in ALL, but are less common in this particular age group. The t(9;22) translocation of the Philadelphia chromosome is particularly common in adults, increases with age, and conveys a poor prognosis 14q32 translocations involving the immunoglobulin heavy chain genes are well recognised in lymphoid malignancies, but are more typical in lymphomas.

Reference:

Harrison CJ. Cytogenetics of paediatric and adolescent acute lymphoblastic leukaemia. British Journal of Haematology 2009; 144; 147-56