title: FCGR3B*03 allele inheritance pattern in Brazilian families and some new variants of gene FCGR3B.
abstract: BACKGROUND
  The FCGR3B gene encoding the FcyRIIIb receptor for immunoglobulin G has three polymorphic forms known as HNA-1a, HNA-1b, and HNA-1c, encoded by the alleles FCGR3B*01, FCGR3B*02, and FCGR3B*03, respectively. It is not clear whether the inheritance of the FCGR3B*03 allele, which encodes the HNA-1c, is linked or not to the other two alleles. The objective of this study was to identify the inheritance pattern of the FCGR3B*03 allele in Brazilians.
  
  
  METHODS
  Blood samples from nine families with at least one FCGR3B*03(+) member, totalizing 47 individuals, were studied. The presence of the FCGR3B*01, FCGR3B*02, and FCGR3B*03 alleles was detected by the polymerase chain reaction with sequence-specific priming method, and all DNA samples were sequenced.
  
  
  RESULTS
  In three of the nine studied families, the FCGR3B*03 was passed down with the FCGR3B*02, while in one family the FCGR3B*03 was inherited in linkage with FCGR3B*01. The other families were not informative regarding FCGR3B*03 inheritance. Sequencing showed for the first time one single-nucleotide polymorphism at Position 264 resulting from a simple substitution C→T; three other different substitutions at Position 230, T→A, T→G; and the presence of three nucleotides at Position 230 (T, G, and A). The previously reported variants FCGR3B*01A227G and FCGR3BG330T were also found.
  
  
  CONCLUSIONS
  In this Brazilian FCGR3B*03(+) group we found that the inheritance of FCGR3B*03 took place by a linkage to FCGR3B*02 or to FCGR3B*01. Linkage of FCGR3B*03 to FCGR3B*02 was the most common. Additionally, we report SNPs that have not been described, suggesting that they might be more common than previously thought.
authors: Disciplina de Hematologia e Hemoterapia, Universidade Federal de São Paulo, São Paulo, Brasil.
authors: Claudia C N
authors: CC
authors: Terzian
authors: Akemi K
authors: AK
authors: Chiba
authors: Viviani C
authors: VC
authors: Santos
authors: Neusa P
authors: NP
authors: Silva
authors: Jose O
authors: JO
authors: Bordin
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution / Q000235:genetics; D001938:Brazil; D005192:Family Health; D005260:Female; D058851:GPI-Linked Proteins / Q000235:genetics; D008040:Genetic Linkage; D014644:Genetic Variation / Q000235:genetics*; D006801:Humans; D008297:Male; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D017452:Receptors, IgG / Q000235:genetics*
chemical_list: C428200:FCGR3B protein, human; D058851:GPI-Linked Proteins; D017452:Receptors, IgG