title: [Molecular genetic analysis for the A3 alleles].
abstract: To study four A(3) subgroup samples identified by serologic tests, among which two belong to a family, three were A(3) subgroup, one was A(3)B subgroup. All four samples were genotyped by PCR-SSP method, and the nucleotide sequences of Exon 6, Exon 7 and part introns at the ABO locus for these samples were detected by ABI Prism 3100 DNA sequencer. Comparison with the consensus of A101 was performed. The results showed that haplotypes of two A(3) subgroups were common A102 allele and O1-2 allele, and haplotypes of one A(3) subgroup were common A102 allele and rare O(1v)-4 allele. Unexpectedly, a synonymous substitution 838C-->T had been found in A allele of the A(3)B subgroup sample, which predict a Leu280Phe alteration. The results suggested that molecular genetic background of the A(3) phenotypes is polymorphic. Possibly, the missense mutation 838C-->T is the molecular genetic basis of A(3)B subgroup that lead to low activity of the glycosyltransferases.
authors.affiliation: Shenzhen Blood Center, Shenzhen Institute of Transfusion Medicine, Shenzhen 518035, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Yu
authors.forename: Yan-Lian
authors.initials: YL
authors.lastname: Liang
authors.forename: Zhi-Hui
authors.initials: ZH
authors.lastname: Deng
authors.forename: Guo-Guang
authors.initials: GG
authors.lastname: Wu
authors.forename: Yu-Qing
authors.initials: YQ
authors.lastname: Su
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Liang-Hong
authors.initials: LH
authors.lastname: Chen
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000483:Alleles; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D002681:China; D004252:DNA Mutational Analysis; D005091:Exons; D005838:Genotype; D006801:Humans; D007438:Introns; D009154:Mutation; D010641:Phenotype; D016133:Polymerase Chain Reaction
chemical_list: D000017:ABO Blood-Group System