FCGR3B gene frequencies and FCGR3 variants in a Chinese population from Zhejiang Province.

The human neutrophil antigens HNA-1a, -1b and -1c play an important role in immune neutropenia. The frequencies of the coding FCGR3B genes were determined in different populations. New FCGR3B variants were also found in some populations. This study investigated the FCGR3B gene frequencies and FCGR3 variants in a Chinese population compared with the results of Northern Germans and African Blacks (Uganda). Our results show that the gene frequencies in 413 healthy Chinese individuals from Zhejiang Province were 0.565 for FCGR3B1, 0.430 for FCGR3B2 and 0.00 for FCGR3B3. The genotype frequency of FCGR3B(null) was 0.48% (2/413). Sequencing of FCGR3 revealed that in seven out of 19 Chinese individuals, cloned and sequenced DNA fragments that exhibited variants caused by single nucleotide exchanges at one or more of the polymorphic positions 141, 147, 227, 266 and 277 in exon 3 also existed in this Chinese population. From the present study, it is concluded that the FCGR3B1 gene is more frequent in a Chinese population from Zhejiang Province than the FCGR3B2 gene, and the FCGR3B3 gene seems to be absent, which is in contrast to studies in the white populations. Gene variants caused by single nucleotide exchanges were found in addition to the well-known forms, but the reason for this remains unclear.