Presence of nucleotide substitutions in transcriptional regulatory elements such as the erythroid cell‐specific enhancer‐like element and theABOpromoter in individuals with phenotypes A3and B3, respectively

• DOI: 10.1111/vox.12136
• Publication Date: 2014-03-06T11:10:45Z
• Authors: Y. Takahashi; K. Isa; R. Sano; T. Nakajima; R. Kubo; K. Takahashi; Y. Kominato; J. Michino; A. Masuno; H. Tsuneyama; S. Ito; K. Ogasawara; M. Uchikawa
• Keywords: 03 medical and health sciences; Enhancer Elements, Genetic; Phenotype; 0302 clinical medicine; Base Sequence; Erythroid Cells; Humans; Promoter Regions, Genetic; Polymorphism, Single Nucleotide; Genetic Association Studies; ABO Blood-Group System

Background and objectives An erythroid cell‐specific regulatory element, referred to as the +5.8‐kb site, has been identified in first intron of human ABO blood group gene. Subsequent studies have revealed involvement deletion or mutation at site phenotypes A m , B AB . We investigated molecular mechanisms involved 3 phenotypes. Materials methods Genomic DNA s were prepared from peripheral seven individuals twelve individuals, nucleotide sequences using PCR sequencing. Promoter assays performed with K562 cells. Results Two single point‐mutations +5893 +5909 on ‐allele found while promoter decreased activity a result each substitution. In two point‐mutation −77 was found, substitution demonstrated reduce activity. Conclusion Nucleotide substitutions transcriptional elements such appear decrease transcription A‐ ‐alleles, resulting reduction B‐antigen expression respectively.