Objective: To investigate the molecular genetics basis for HLA novel allele HLA-A*3308 in Chinese population.
Methods: DNA was extracted from whole blood by PEL-FREEZ DNA extraction kit. The amplification of HLA-A exons 1-8 of the proband was preformed by PCR and the amplified product was cloned with TOPO cloning sequencing kit to split the two alleles apart. Both strands of exons 2, 3 and 4 of chosen clones were sequenced. The PCR-SSP was performed to confirm the mutations detected by sequencing.
Results: The sequencing results showed HLA-A alleles of the proband as A*0201 and the novel allele. The sequences of the novel allele have been submitted to GenBank (DQ089631, DQ089632, DQ089633). BLAST analysis showed that the novel allele got the difference from A*3303 by five nucleotides at positions 240 A>T, 256C>G, 259A>G, 261C>G and 270T>A in exon 2. This resulted in three amino acids changes from Arg to Gly at codon 62, Asn to Glu at codon 63 and Asn to Lys at codon 66.
Conclusion: This allele is a novel allele and has been officially named A*3308 by the WHO Nomenclature Committee.