title: A novel missense mutation nt737T>G of JK gene with Jk(a-b-) phenotype in Chinese blood donors.
abstract: OBJECTIVE
  The aim of this study was to investigate the molecular mechanism of the JK-null phenotype in the Chinese population.
  
  
  BACKGROUND
  The Jk(a-b-) phenotype is vanishingly rare and the molecular basis differs between ethnic groups. The information regarding the molecular basis of JK-null alleles in the Chinese population is limited.
  
  
  METHODS
  Three unrelated Jk(a-b-) phenotype donors were selected from 52 260 randomly blood samples through the urea lysis test and serological analysis. The JK gene-coding regions were amplified by the polymerase chain reaction and the products were sequenced directly.
  
  
  RESULTS
  Sequencing results revealed that one sample of JK(*) B alleles carried the well-known Polynesian Jk(a-b-) mutation IVS5-1g>a. Another null allele, also on the JK(*) B background, presented with two heterozygous missense mutation, including nt222C>A(Asn74Lys) in exon 5 and nt896G>A(Gly299Glu) in exon 9. The third null allele carried two heterozygous missense mutations, nt222C>A and a novel allele nt737T>G(Leu246Arg) in exon 8. The family investigation revealed that the proband was JK(*) A(737T>G)/JK(*) B(222C>A).
  
  
  CONCLUSIONS
  The Jk(a-b-) phenotype in the Chinese population shows several different molecular mechanisms. A novel missense mutation nt737T>G of JK gene was found as associated with Jk(a-b-) phenotype.
authors: Immunohematology Laboratory, Jiangsu Province Blood Center, Nanjing, China.
authors: L
authors: L
authors: Ma
authors: Y C
authors: YC
authors: Liu
authors: S W
authors: SW
authors: Zhu
authors: W J
authors: WJ
authors: Hu
authors: X
authors: X
authors: Chen
authors: M
authors: M
authors: Xue
authors: L
authors: L
authors: Zhen
authors: M H
authors: MH
authors: Wu
authors: Y
authors: Y
authors: Liu
authors: J
authors: J
authors: Sun
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution; D044466:Asian People; D002681:China; D005091:Exons; D006579:Heterozygote; D006801:Humans; D007667:Kidd Blood-Group System / Q000235:genetics*; D020125:Mutation, Missense
chemical_list: D007667:Kidd Blood-Group System
keywords: Chinese blood donors; Jk(a−b−) phenotype; missense mutation; sequence