BACKGROUND: Human neutrophil antigen-1c (HNA-1c) (SH) has been described as the third alloantigen of the Fc receptor type IIIb (FcgammaRIIIb) for IgG beside the known alloantigens HNA-1a (NA1) and HNA-1b (NA2). Controversy exists on the assignment of the HNA-1c coding gene to the @entity4070 locus and on a possible linkage between the HNA-1c and HNA-1a coding genes. STUDY DESIGN AND METHODS: Two hundred sixty northern German blood donors and 43 individuals from Uganda were typed for @entity4070 *1 (NA1), @entity4070 *2 (NA2), and @entity4070 *3 (SH) by allele-specific PCR. In a subset of @entity4070 *3-positive probands, PCR-amplified @entity4071 fragments were subcloned and sequenced. Transmission of @entity4070 *3 was analyzed in family studies. A possible correlation with the FcgammaRIIIb alloantigen expression was investigated by flow cytometry. RESULTS: In the northern German population, @entity4070 *3 was found exclusively in individuals carrying @entity4070 *1 independent of the existence of @entity4070 *2 at a frequency of 5 percent. In the individuals from Uganda, each possible combination of @entity4070 *1, @entity4070 *2, and @entity4070 *3 was detected. @entity4070 *3 frequency was 34.9 percent. Within both populations, some individuals carried each of the three genotypes. DNA sequencing revealed new @entity4071 variants caused by single @entity377 exchanges at the typical polymorphic positions. In one individual, six different @entity4071 variants were detected. CONCLUSION: The coincidence of the three known @entity4070 alleles varies within the population of Germany and Uganda. Three simultaneous @entity4070 forms may be explained by two gene loci, but the basis of the high number of different variants in some individuals still remains unclear. Possible explanations may be a hypermutation mechanism or a number of @entity4071 higher than expected hitherto.

XXXX variants and expression of human neutrophil antigen-1a, -1b, and -1c in the populations of northern Germany and Uganda.

@entity4071 :: ('2214', 'Gene') :: ['FCGR3'] @entity4070 :: ('2215', 'Gene') :: ['FCGR3B'] @entity377 :: ('CHEBI:36976', 'Chemical') :: ['nucleotide']
@entity4071 :: (2214,Gene) :: ['FCGR3']
