KIR3DL3 allelic diversity: six new alleles exhibit both conservative and non-conservative substitutions.

KIR3DL3 alleles were characterized in two families and one unrelated individual. Based on exon 2-9 nucleotide sequences, six novel alleles, 3DL3*00402, *005, 006, 007, 00801, 00802, were identified bringing the total number of known alleles to 11. Compared with 3DL3001, the six new alleles differ by from three to nine nucleotides and from three to four amino acids. The new alleles double the number of known polymorphic positions to 18 with variation in exons encoding the extracellular domains, transmembrane region, and a portion of the cytoplasmic tail. Many of the nucleotide substitutions are shared among alleles of 3DL3 or other KIR loci, but five were found only in single 3DL3 alleles. Comparison of intron sequences among individuals carrying the same allele showed a modest number of substitutions with the exception of 3DL3001 which differed substantially in its intron sequences. Two alleles sharing coding region sequences, 3DL300201 and 3DL300202, were also substantially different in intron sequences.