title: [Identification of an ABx09 phenotype of ABO subtype].
abstract: OBJECTIVE
  To analyze the molecular basis for an individual with ABx09 phenotype of ABO subtype.
  
  
  METHODS
  The ABO group antigens on red blood cells of the proband were identified by monoclonal antibodies, and the ABO antibody in serum was detected by standard A, B, O cells. The exons 1 to 7 of ABO gene were amplified by polymerase chain reaction (PCR) respectively and the PCR products were sequenced directly. The amplified products for exons 5 to 7 were also cloned by TOPO TA cloning sequencing kit to split the two alleles apart, selected colonies were sequenced bidirectionally for exons 5 to 7 of the ABO gene. The samples of the proband's parents were collected, then serological test of the blood group and sequence analysis for exons 6 and 7 of ABO gene were preformed.
  
  
  RESULTS
  Both A and B antigens were detected on red blood cells of the proband and there was anti-B antibody in the serum. There was no G deletion at position 261, while 297AG in exon 6, 467CT, 526CG, 657CT, 703GA, 796CA, 803GC, 889GA and 930GA heterozygote in exon 7 were detected by direct DNA sequencing, which can be assigned for A102Bx09 genotype. After cloning and sequencing, two alleles A102 and Bx09 were obtained. The sequence of Bx09 had one nucleotide changes (G to A) at position 889 compared with that of B101, which resulted in an amino acid change of Glu to Lys at 297 position. The Bx09 in the proband was inherited from her mother by family investigation.
  
  
  CONCLUSIONS
  G to A at nt889 of alpha-1,3 galactosyltransferasegene can result in Bx09 phenotype, with the presence of anti-B antibody in serum.
authors: Blood Center of Zhejiang Province, Zhejiang, People's Republic of China.
authors: Xiao-zhen
authors: XZ
authors: Hong
authors: Yan-ling
authors: YL
authors: Ying
authors: Xian-guo
authors: XG
authors: Xu
authors: Kai-rong
authors: KR
authors: Ma
authors: Xiao-fei
authors: XF
authors: Lan
authors: Ying
authors: Y
authors: Liu
authors: Fa-ming
authors: FM
authors: Zhu
authors: Hang-jun
authors: HJ
authors: Lv
authors: Li-xing
authors: LX
authors: Yan
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics* / Q000378:metabolism*; D000293:Adolescent; D000483:Alleles; D001483:Base Sequence; D001788:Blood Grouping and Crossmatching; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D010375:Pedigree; D010641:Phenotype
chemical_list: D000017:ABO Blood-Group System