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Allelic polymorphisms of human Fcγ receptor IIa and Fcγ receptor IIIb among distinct groups in Brazil
Author(s) -
Kuwano Sachie T.,
Bordin José O.,
Chiba Akemi K.,
Mello Adriana B.,
Figueiredo Maria S.,
VieiraFilho João P.B.,
Fabron Antonio,
Kerbauy José
Publication year - 2000
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1046/j.1537-2995.2000.40111388.x
Subject(s) - allele , allele frequency , biology , amazon rainforest , single nucleotide polymorphism , immunology , gene , genetics , microbiology and biotechnology , genotype , medicine , ecology
BACKGROUND: The FcγRIIA gene is expressed in two polymorphic forms, R131 and H131, which differ by the replacement of histidine by arginine at position 131. The FCGR3B ( FcγRIIIB ) gene exists in two allelic isoforms, known as FCGR3B1 ( FcγRIIIB‐NA1 ) and FCGR3B2 ( FcγRIIIB‐NA2 ), which differ in nucleotides 141, 147, 227, 277, and 349. An additional polymorphism is the SH antigen that is associated with the FCGR3B3 ( FcγRIIIB‐SH ) allele. STUDY DESIGN AND METHODS: By use of a PCR with allele‐specific primers, the allelic polymorphisms of FcγRIIA and FcγRIIIB were determined among 263 unrelated Brazilian subjects, including Amazon Indians (n = 92), blood donors (n = 85), and patients with sickle cell disease (SCD) (n = 86). RESULTS: Amazon Indians had a significantly higher frequency of the R131 allele than did blood donors and SCD patients (0.91 vs. 0.55 vs. 0.55; p<0.001). NA1 and NA2 gene frequencies were found to be 0.67 and 0.21 for Amazon Indians, 0.58 and 0.42 for blood donors, and 0.61 and 0.39 for SCD patients, respectively. The FcγRIIIB‐SH allele was absent from the Amazon Indians, but 9 (10.6%) blood donors and 10 (11.6%) SCD patients expressed this allele. CONCLUSION: Overall, the data indicate that the distribution of the FcγRIIIB alleles is significantly different in Amazon Indians from the distribution in Brazilian blood donors or African Brazilian patients with SCD, but that it is similar to the distributions reported in Asian populations. Moreover, the distribution of the FcγRIIA and FcγRIIIB alleles among Brazilian blood donors and SCD patients is comparable to the distributions reported in whites from the United States and Europe.