BCR-ABL Translocation in Pediatric Acute Lymphoblastic Leukemia in Southern India

Abstract

Cytogenetics and polymerase chain reaction (PCR) based assays provide important information regarding biologically defined and prognostically relevant subgroups in acute leukemias. We utilized karyotyping and molecular analysis by reverse transcriptase PCR for the BCR-ABL translocation, in addition to morphological study, cytochemistry and immunophenotyping, to study 24 cases of pediatric acute lymphoblastic leukemia (ALL). Our objective was to determine the frequency of the BCRABL translocation in childhood ALL from southern India. Karyotyping showed one case of hyperdiploidy, one case of t (12; 21) translocation and one case of 46, XY-21?mar. The BCR-ABL translocation was found in 8.3% of these cases. One of these was a cryptic translocation, the karyotype being normal. BCR-ABL positivity in ALL is associated with aggressive disease and has been shown to be a poor prognostic factor, especially in children.

Acute lymphoblastic leukemia, the Indian scenario

“…The study conducted by K.S Tsang et al, 16 showed TEL/AML rearrangements had better induction response and longer complete remission. In a study by D Sugapriya et al, 17 ABL-BCR positivity was seen in 8.3% patients in southern India, which was 9.7% in our study. Long-term survival rates in pediatric ALL with BCR-ABL positive is around 80%, which drops down to 30% in adults, with 86% overall survival at 6 years in our study.…”

Clinico-epidemiological features and response in childhood acute lymphoblastic leukemia at regional cancer center of Northeast India

“…[10,14,15] We found higher proportions of BCR-ABL positivity (43% vs. 8.3% from a South Indian study). [16] We did not found any CNS-positive disease at baseline, as compared to 3%-6% positivity reported in various Indian studies. [12,17,18] We also found higher early deaths in our study (21% vs. 10%-12%) compared to other studies from India.…”

The Frequency of BCR-ABL1 Fusion Transcripts in Iranian Patients with Three Different Types of Leukemia

“…It is also reported in 10% to 20% of adults and in 2% to 5% of children with acute lymphoblastic leukemia (ALL), and in very rarely cases of acute myeloid leukemia (AML) [1,3].…”

“…In 5% of CML patients, both b3a2 and b2a2 transcripts can be made as a result of alternative splicing [1,3]. In approximately 60% of Philadelphia chromosome positive ALL patients and in some cases of CML and AML the BCR breakpoint falls within the minor breakpoint cluster region (mbcr ) that causes hybrid transcript containing an e1a2 junction, which is translated into a 190 kDa fusion protein (p190 BCR-ABL ) [4,5].…”