FCGR3B*03 allele inheritance pattern in Brazilian families and some new variants of gene FCGR3B

Transfusion. 2012 Mar;52(3):629-34. doi: 10.1111/j.1537-2995.2011.03326.x. Epub 2011 Sep 2.

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.

Study design and 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.

Conclusion: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Substitution / genetics
  • Brazil
  • Family Health
  • Female
  • GPI-Linked Proteins / genetics
  • Genetic Linkage
  • Genetic Variation / genetics*
  • Humans
  • Male
  • Pedigree
  • Polymorphism, Single Nucleotide / genetics*
  • Receptors, IgG / genetics*

Substances

  • FCGR3B protein, human
  • GPI-Linked Proteins
  • Receptors, IgG