title: A family study of the Chinese Rhnull individual of the regulator type: a novel single missense mutation identified in RHAG gene.
abstract: BACKGROUND
  Rh(null)  is a rare autosomal recessive disorder, and Rh(null)  of the regulator type may result from mutation of the RHAG gene, which encodes RhAG glycoprotein and modulates Rh antigen expression. This study described the molecular genetic analysis of a Chinese Rh(null)  family and identified a novel mutation in the RHAG gene.
  
  
  METHODS
  RBCs from the Rh(null)  family members were analyzed for Rh phenotype by standard methods. DNA sequences of all 10 exons of RHAG gene were analyzed using genomic DNA by polymerase chain reaction and direct DNA sequencing.
  
  
  RESULTS
  Genomic DNA analyses showed that a 672C>A mutation in Exon 5 of the RHAG gene was present at the homozygous state in DH and at the heterozygous state in the other members of the Rh(null)  family. The 672C>A missense mutation converted serine into arginine at Position 224 in the Transmembrane Segment 7 of RhAG glycoprotein.
  
  
  CONCLUSIONS
  These findings provide evidence that the 672C>A missense mutation in the RHAG gene could result in Rh(null)  of the regulator type, and the single-amino-acid change (Ser to Arg) might be critical for assembly of the Rh antigen complex within the membrane.
authors.affiliation: Department of Blood Immunology, Institute of Blood Transfusion, Chinese Academy of Medical Sciences, West China Hospital, Sichuan University, Chengdu, Sichuan.
authors.forename: Li
authors.initials: L
authors.lastname: Tian
authors.forename: Ning
authors.initials: N
authors.lastname: Song
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Yao
authors.forename: Mei
authors.initials: M
authors.lastname: Huang
authors.forename: Li
authors.initials: L
authors.lastname: Hou
mesh_terms: D000328:Adult; D019943:Amino Acid Substitution; D044466:Asian People; D001798:Blood Proteins / Q000096:biosynthesis / Q000235:genetics*; D002681:China; D004252:DNA Mutational Analysis / Q000379:methods; D004910:Erythrocyte Membrane / Q000235:genetics / Q000378:metabolism; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics*; D020125:Mutation, Missense; D016133:Polymerase Chain Reaction / Q000379:methods
chemical_list: D001798:Blood Proteins; D008562:Membrane Glycoproteins; C498523:RHAG protein, human