title: Frequency and Clinical Characteristics of Intrachromosomal Amplification of Chromosome 21 in Korean Childhood B-lineage Acute Lymphoblastic Leukemia.
abstract: BACKGROUND
  Intrachromosomal amplification of chromosome 21 (iAMP21) is known to be associated with poor prognosis in B-cell ALL (B-ALL). To determine the frequency and clinical characteristics of iAMP21 in Korean B-ALL patients, we performed FISH and multiplex ligation-dependent probe amplification (MLPA) analyses.
  
  
  METHODS
  A total of 102 childhood B-ALL patients were screened with ETV6-RUNX1 FISH probes (Abbott Molecular, USA). The presence of an iAMP21 was confirmed by using MLPA P327 iAMP21-ERG probemix (MRC Holland, The Netherlands).
  
  
  RESULTS
  iAMP21 was detected in one of the screened B-ALL patients (1/102 patients, 1.0%) who presented the ALL immunophenotype and complex karyotype at initial diagnosis. The patient relapsed twice after bone marrow transplantation. MLPA showed 12.5-Mb and 4.28-Mb regions of amplification and deletion, respectively.
  
  
  CONCLUSIONS
  The frequency of iAMP21 is considerable in Korean pediatric patients. Our report suggests that iAMP21 in childhood B-ALL has very unfavorable impact on patient's prognosis. Additional methods such as MLPA analysis is essential to rule out patients with equivocal interphase FISH results.
authors.affiliation: Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jieun
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Yonsei Cancer Research Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Chuhl Joo
authors.initials: CJ
authors.lastname: Lyu
authors.affiliation: Department of Laboratory Medicine, Hallym University College of Medicine, Kangnam Sacred Heart Hospital, Seoul, Korea. ugine01@naver.com.
authors.forename: Saeam
authors.initials: S
authors.lastname: Shin
authors.affiliation: Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea. LEE.ST@yuhs.ac.
authors.forename: Seung Tae
authors.initials: ST
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jong Rak
authors.initials: JR
authors.lastname: Choi
mesh_terms: D000293:Adolescent; D044466:Asian People / Q000235:genetics*; D001402:B-Lymphocytes / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D002891:Chromosomes, Human, Pair 21; D050676:Core Binding Factor Alpha 2 Subunit / Q000235:genetics; D015342:DNA Probes / Q000378:metabolism; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D060885:Multiplex Polymerase Chain Reaction; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000235:genetics; D050783:Proto-Oncogene Proteins c-ets / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics; D056910:Republic of Korea; D014178:Translocation, Genetic; D055815:Young Adult; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D050676:Core Binding Factor Alpha 2 Subunit; D015342:DNA Probes; D050783:Proto-Oncogene Proteins c-ets; D012097:Repressor Proteins; D000097764:ETS Translocation Variant 6 Protein; C493728:RUNX1 protein, human
keywords: Acute lymphoblastic leukemia; Childhood; ERG; FISH; Korean; MLPA; RUNX1; iAMP21