Incidence, clinical characteristics and early treatment outcome in Indian patients of childhood acute lymphoblastic leukemia with ALL-1 gene rearrangement.

In a series of 185 patients (median age 7 years) of acute lymphoblastic leukaemia (ALL) from India, the overall incidence of ALL-1 gene rearrangement using the Southern blot technique was 11.4% (21/185). The incidence amongst the infants (age < or = 1 year, 70%) was significantly higher when compared to patients > 1 - < or = 10 years (7.4%, P = 0.00001) as well as > 10 years old (9.3%, P = 0.0001). ALL-1 gene rearrangement was associated with significantly higher WBC count (P = 0.01) and CD10 negativity (P = 0.00000001). Complete remission (CR) and relapse rates in 98 patients evaluable for response to therapy on a uniform therapy protocol was independent of ALL-1 gene status.