Novel BCR–ABL transcript containing an intronic sequence insert in a patient with Philadelphia‐positive acute lymphoblastic leukaemia

• Published in: British journal of haematology 2000-09, Vol.110 (4), p.867-870
• Main Authors: Hirota, Masako, Hidaka, Eiko, Ueno, Ichiro, Ishikawa, Masayo, Asano, Naoko, Yamauchi, Kazuyoshi, Ishida, Fumihiro, Tozuka, Minoru, Katsuyama, Tsutomu
• Format: Article
• Language: English
• Subjects: acute lymphoblastic leukaemia; Aged; Amino Acid Sequence; Base Sequence; BCR–ABL; Biological and medical sciences; Codon, Terminator; Female; Fusion Proteins, bcr-abl; Hematologic and hematopoietic diseases; Humans; Introns; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Medical sciences; Molecular Sequence Data; Philadelphia chromosome; Precursor Cell Lymphoblastic Leukemia-Lymphoma - genetics; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - analysis; RT‐PCR; translocation; Translocation, Genetic
• ISSN: 0007-1048; 1365-2141
• DOI: 10.1046/j.1365-2141.2000.02205.x

In a patient with Philadelphia chromosome‐positive acute lymphoblastic leukaemia (ALL), a novel variant of the chimaeric BCR–ABL mRNA transcript was detected by reverse transcription polymerase chain reaction (RT‐PCR). Sequencing revealed the novel transcript to be a chimaeric mRNA produced by fusion of the BCR exon 14 (b3) to the ABL exon a2 with a 49‐base pair (bp) insertion of an ABL intron 1b sequence between them. The insertion of the 49 bp introduced a stop codon. These data show that this variant of the chimaeric mRNA would not be translated into the p210 BCR–ABL protein. This could be one of the explanations as to why clinically the patient has responded well to therapy and continues to follow a mild clinical course.