[Cloning and sequencing of KIR2DL1 framework gene cDNA and identification of a novel allele].

OBJECTIVE: To develop an assay for cDNA cloning and haplotype sequencing of KIR2DL1 framework gene and determine the genotype of an ethnic Han from southern China.

METHODS: Total RNA was isolated from peripheral blood sample, and complementary DNA (cDNA) transcript was synthesized by RT-PCR. The entire coding sequence of the KIR2DL1 framework gene was amplified with a pair of KIR2DL1-specific PCR primers. The PCR products with a length of approximately 1.2 kb were then subjected to cloning and haplotype sequencing.

RESULTS: A specific target fragment of the KIR2DL1 framework gene was obtained. Following allele separation, a wild-type KIR2DL1*00302 allele and a novel variant allele, KIR2DL1*031, were identified. Sequence alignment with KIR2DL1 alleles from the IPD-KIR Database showed that the novel allele KIR2DL1*031 has differed from the closest allele KIR2DL1*00302 by a non-synonymous mutation at CDS nt 188A>G (codon 42 GAG>GGG) in exon 4, which has caused an amino acid change Glu42Gly. The sequence of the novel allele KIR2DL1*031 was submitted to GenBank under the accession number KP025960 and to the IPD-KIR Database under the submission number IWS40001982. A name KIR2DL1*031 has been officially assigned by the World Health Organization (WHO) Nomenclature Committee.

CONCLUSION: An assay for cDNA cloning and haplotype sequencing of KIR2DL1 has been established, which has a broad applications in KIR studies at allelic level.