[FCGR3B gene frequencies and FCGR3 gene variants in Chinese: a study in 487 Chinese individuals from Zhejiang Province].

Objective: To investigate the FCGR3B gene frequencies and FCGR3 variants in a Chinese population from Zhejiang Province.

Methods: DNA was extracted from the blood specimens of 487 healthy blood donors from Zhejiang Province. The FCGR3B gene frequencies were determined by polymerase chain reaction with sequence-specific primers (PCR-SSP). The 19 specimens with 3 different FCGR3B genotypes underwent FCGR3 gene cloning and sequencing.

Results: The gene frequencies of FCGR3B(*1), FCGR3B(*2), and FCGR3B(*3) in these 487 individuals were 0.564, 0.429, and 0.000 respectively. The genotype frequency of FCGR3B(null) was 0.62% (3/487). Sequencing of FCGR3 revealed that in 7 out of the 19 Chinese individuals 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.

Conclusion: FCGR3B(*1) gene is more frequent in a Chinese population from Zhejiang Province than the FCGR3B(*2) gene, and the FCGR3B(*3) gene seems to be absent. Gene variants caused by single nucleotide exchanges are found in addition to the well known forms, but the reason for this remains unclear.