title: Frequency of rare BCR-ABL1 fusion transcripts in chronic myeloid leukemia patients.
abstract: BACKGROUND
  The hallmark of chronic myeloid leukemia (CML) is the presence of Philadelphia chromosome, its resultant fusion transcript (BCR-ABL1), and fusion protein (p210). Alternate breakpoints in BCR (m-bcr, μ-bcr, and others) or ABL1 result in the expression of few rare fusion transcripts (e19a2, e1a2, e13a3, e14a3) and fusion proteins (p190, p200, p225) whose exact clinical significance remains to be determined.
  
  
  METHODS
  Our study was designed to determine the type and frequency of BCR-ABL1 fusion transcripts in 1260 CML patients and to analyze the prognosis and treatment response in patients harboring rare BCR-ABL1 fusion transcripts.
  
  
  RESULTS
  The frequency of various BCR-ABL1 fusion transcripts was as follows: e14a2 (60%), e13a2 (34.3%), e1a2 (1.2%), e1a2 + e13a2 (2.0%), e1a2 + e14a2 (1.8%), e19a2 (0.3%), and e14a3 (0.3%). CML patients with e1a2 transcripts had higher rates of disease progression, resistance, or suboptimal response to imatinib and failed to achieve major molecular response.
  
  
  CONCLUSIONS
  Characterization of the specific fusion transcript in CML patients is important owing to the difference in prognosis and response to therapy in addition to the conventional need for monitoring treatment response. CML patients with e1a2 transcripts have to be closely monitored due to the high incidence of disease progression and treatment resistance/failure.
authors.affiliation: Department of Haematology, Christian Medical College, Vellore, India.
authors.forename: A K
authors.initials: AK
authors.lastname: Arun
authors.affiliation: Department of Haematology, Christian Medical College, Vellore, India.
authors.forename: A
authors.initials: A
authors.lastname: Senthamizhselvi
authors.affiliation: Department of Haematology, Christian Medical College, Vellore, India.
authors.forename: S
authors.initials: S
authors.lastname: Mani
authors.affiliation: Department of Haematology, Christian Medical College, Vellore, India.
authors.forename: K
authors.initials: K
authors.lastname: Vinodhini
authors.affiliation: Department of Haematology, Christian Medical College, Vellore, India.
authors.forename: N B
authors.initials: NB
authors.lastname: Janet
authors.affiliation: Department of Haematology, Christian Medical College, Vellore, India.
authors.forename: K M
authors.initials: KM
authors.lastname: Lakshmi
authors.affiliation: Department of Haematology, Christian Medical College, Vellore, India.
authors.forename: A
authors.initials: A
authors.lastname: Abraham
authors.affiliation: Department of Haematology, Christian Medical College, Vellore, India.
authors.forename: B
authors.initials: B
authors.lastname: George
authors.affiliation: Department of Haematology, Christian Medical College, Vellore, India.
authors.forename: A
authors.initials: A
authors.lastname: Srivastava
authors.affiliation: Cytogenetics Unit, Christian Medical College, Vellore, India.
authors.forename: V M
authors.initials: VM
authors.lastname: Srivastava
authors.affiliation: Department of Haematology, Christian Medical College, Vellore, India.
authors.forename: V
authors.initials: V
authors.lastname: Mathews
authors.affiliation: Department of Haematology, Christian Medical College, Vellore, India.
authors.forename: P
authors.initials: P
authors.lastname: Balasubramanian
mesh_terms: D018572:Disease-Free Survival; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics / Q000378:metabolism / Q000401:mortality* / Q000628:therapy; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D015996:Survival Rate
chemical_list: C581634:BCR-ABL1 fusion protein, human; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D016044:Fusion Proteins, bcr-abl
keywords: 
  BCR-ABL1
  ; CML; e1a2 transcripts; rare fusion transcripts