title: Screening of Variations in CD22 Gene in Children with B-Precursor Acute Lymphoblastic Leukemia.
abstract: BACKGROUND
  CD22 is expressed on the surface of B-cell lineage cells from the early progenitor stage of pro-B cell until terminal differentiation to mature B cells. It plays a role in signal transduction and as a regulator of B-cell receptor signaling in B-cell development.
  
  
  OBJECTIVE
  We aimed to screen exons 9-14 of the CD22 gene, which is a mutational hot spot region in B-precursor acute lymphoblastic leukemia (pre-B ALL) patients, to find possible genetic variants that could play role in the pathogenesis of pre-B ALL in Turkish children.
  
  
  METHODS
  This study included 109 Turkish children with pre-B ALL who were diagnosed at Losante Hospital for Children with Leukemia. Genomic DNA was extracted from both peripheral blood and bone marrow leukocytes. Gene amplification was performed with PCR, and all samples were screened for the variants by single strand conformation polymorphism. Samples showing band shifts were sequenced on an automated sequencer.
  
  
  RESULTS
  In our patient group a total of 9 variants were identified in the CD22 gene by sequencing: a novel variant in intron 10 (T2199G); a missense variant in exon 12; 5 intronic variants between exon 12 and intron 13; a novel intronic variant (C2424T); and a synonymous in exon 13. Thirteen of 109 children (11.9%) carried the T2199G novel intronic variant located in intron 10, and 17 of 109 children (15.6%) carried the C2424T novel intronic variant.
  
  
  CONCLUSIONS
  Novel variants in the CD22 gene in children with pre-B ALL in Turkey that are not present, in the Human Gene Mutation Database or NCBI SNP database, were found.
authors.affiliation: 1 Cancer Genetic Research Laboratory, Lösante Hospital , Ankara, Turkey .
authors.forename: Deniz
authors.initials: D
authors.lastname: Aslar Oner
authors.affiliation: 1 Cancer Genetic Research Laboratory, Lösante Hospital , Ankara, Turkey .
authors.forename: Dilara Fatma
authors.initials: DF
authors.lastname: Akin
authors.affiliation: 1 Cancer Genetic Research Laboratory, Lösante Hospital , Ankara, Turkey .
authors.forename: Kadir
authors.initials: K
authors.lastname: Sipahi
authors.affiliation: 1 Cancer Genetic Research Laboratory, Lösante Hospital , Ankara, Turkey .
authors.forename: Mine
authors.initials: M
authors.lastname: Mumcuoglu
authors.affiliation: 2 Department of Pediatric Hematology/Oncology, Lösante Hospital , Ankara, Turkey .
authors.forename: Ustun
authors.initials: U
authors.lastname: Ezer
authors.affiliation: 2 Department of Pediatric Hematology/Oncology, Lösante Hospital , Ankara, Turkey .
authors.forename: A Emin
authors.initials: AE
authors.lastname: Kürekci
authors.affiliation: 3 TOBB-ETÜ Hospital , Ankara, Turkey .
authors.forename: Nejat
authors.initials: N
authors.lastname: Akar
mesh_terms: D000293:Adolescent; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D005091:Exons; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007223:Infant; D007438:Introns; D008297:Male; D009154:Mutation; D011110:Polymorphism, Genetic; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000378:metabolism; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000378:metabolism; D051918:Sialic Acid Binding Ig-like Lectin 2 / Q000235:genetics* / Q000378:metabolism; D014421:Turkey
chemical_list: C497867:CD22 protein, human; D051918:Sialic Acid Binding Ig-like Lectin 2