Introduction
Infants account for 2-5% and 6-14% of childhood acute lymphoblastic
leukemias and acute myeloid leukemias, respectively (1). Patients in
this group are characterized by hyperleukocytosis, hepatosplenomegaly,
absence of CD 10 expression in the blasts, MLL rearrangement, and
central nerve system involvement. The findings of extramedullary
invasion may be the first symptom without any abnormality in peripheral
blood. These features are associated with poor prognosis and treatment
success is low despite intensive chemotherapy (2-4). MLL (11q23)
rearrangement is present in 66% of infant acute lymphoblastic leukemia
(ALL)s and 35% of acute myeloid leukemia (AML)s . Among infant
leukemias with t(4; 11) event-free survival of ALL are lower than that
of AMLs (5). Besides, clinical features change according to the opposite
chromosome where MLL is translocated. Since it is the most common
genetic feature, studies on infant leukemia focus on MLL rearrangements.
Rare translocations are also seen in infant leukemias. t (5; 15) which
is very rare has been reported in 7 infant ALL cases (4,6). In addition,
various anomalies have been reported in infant leukemias. However, the
relationship of these anomalies with leukemia is uncertain (7). Here we
report a case with t (5; 15) (p15; q11.2) infant leukemia and
ectrodactyly.