Incidence of internal tandem duplications and D835 mutations of FLT3 gene in chronic myeloid leukemia patients from Southern India.

Objective: To screen two important FLT3 mutations (internal tandem duplication (ITD) and D835 point mutations) in chronic myeloid leukemia (CML) patients from Southern India and report their incidence.
Methods: Screened 350 CML patients and 350 controls for the two FLT3/mutations through polymerase chain reaction and restriction fragment length polymorphism methods.
Results: ITDs were detected in 12 of the 350 CML patients (3.4%) and D835 mutations in only four cases (1.14%), relatively low in frequency as compared to those reported earlier from non-Indian populations. None of the cases showed simultaneous occurence of both ITD and D835 mutations.
Discussion: These FLT3 mutations seem to be very rare in CML, and it is possible that these could be found only in a subset of patients who are in the progressive stage and/or with varied drug response. Prospective studies are needed to confirm the role of FLT3 mutations in CML pathogenesis, which may help devising therapeutic interventions.