title: Classification of standard alleles of the MN blood group system.
abstract: OBJECTIVE
  We had classified the M alleles of the MN blood group system into two subtypes, M(G) (standard M) and M(T), based on a G/T substitution in intron 1 of the glycophorin A (GPA) gene. This study provides further study on nucleotide sequences of M(G), M(T) and N alleles to profile the new allele, M(T).
  
  
  METHODS
  M(G), M(T) and N alleles of the GPA gene were amplified using GPA gene-specific primers to avoid co-amplification of the genes of glycophorins B and E. Then the 5'-flanking region, exons 1-7 and introns 1-4 of the alleles were analyzed by DNA sequencing.
  
  
  RESULTS
  There were 17 nucleotide substitutions and deletions between M(G) (standard M) and N alleles. Ten of the M(T) nucleotides were M(G)-type but the other 7 were N-type. M(T) allele also showed one base change and one deletion that were observed in neither the M(G) nor the N allele. Moreover, we found nucleotide substitutions within each allele, allowing further classification of the alleles.
  
  
  CONCLUSIONS
  By the sequence data of M(G), M(T) and N alleles, the three alleles could be further classified into M101 and M102, M201 and M202, and N101 and N102, respectively.
authors: Department of Legal Medicine, Kansai Medical University, Moriguchi, Japan. akane@takii.kmu.ac.jp
authors: A
authors: A
authors: Akane
authors: H
authors: H
authors: Mizukami
authors: H
authors: H
authors: Shiono
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution; D001483:Base Sequence; D005091:Exons / Q000235:genetics; D006021:Glycophorins / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D007438:Introns / Q000235:genetics; D007564:Japan; D008951:MNSs Blood-Group System / Q000235:genetics*; D008969:Molecular Sequence Data; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D016415:Sequence Alignment; D017384:Sequence Deletion; D012689:Sequence Homology, Nucleic Acid; D009626:Terminology as Topic
chemical_list: D006021:Glycophorins; D008951:MNSs Blood-Group System