Study of polymorphisms of HLA class Ⅰ (-A, -B, -C) and class Ⅱ (DRB1, DQA1, DQB1, DPA1, DPB1) genes among ethnic Hans from Southern China / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the genetic polymorphisms of human leukocyte antigen (HLA)- A, B, C, DRB1, DQA1, DQB1, DPA1and DPB1among ethnic Hans from southern China.</p><p><b>METHODS</b>481 randomly selected individuals were genotyped using a polymerase chain reaction (PCR) sequence-based typing (SBT) method for the above genes. Their allele frequencies were determined by direct counting.</p><p><b>RESULTS</b>In total, 28 HLA-A, 57 HLA-B, 28 HLA-C, 40 HLA-DRB1, 18 HLA-DQA1, 17 HLA-DQB1, 6 HLA-DPA1and 21 HLA-DPB1alleles were identified. Among these, common alleles (with allelic frequencies > 0.05) included A*1101, A*2402, A*0207, A*3303, A*0201, B*40:01, B*46:01, B*58:01, B*13:01, B*15:02, C*01:02, C*07:02, C*03:04, C*03:02, C*08:01, C*03:03, C*04:01, DRB1*09:01, DRB1*15:01, DRB1*12:02, DRB1*08:03, DRB1*03:01, DRB1*04:05, DRB1*11:01, DQA1*01:02, DQA1*03:02, DQA1*03:03, DQA1*06:01, DQA1*01:03, DQA1*05:05, DQA1*01:04, DQA1*03:01, DQA1*05:01, DQB1*03:01, DQB1*03:03, DQB1*06:01, DQB1*05:02, DQB1*03:02, DQB1*02:01, DQB1*03:02, DQB1*06:02, DPA1*02:02, DPA1*01:03, DPA1*02:01, DPB1*05:01, DPB1*02:01, DPB1*13:01, DPB1*04:01and DPB1*02:02.For each of the locus, the overall frequencies of common alleles were 75.57%, 52.81%, 78.28%, 62.16%, 86.70%, 77.23%, 95.32% and 81.59%, respectively.</p><p><b>CONCLUSION</b>The allelic frequencies of the 8 selected HLA loci among ethnic Hans from southern China may served as a reference for anthropology, legal medicine, transplantation and disease association studies.</p>

Sequencing analysis of exons 1,5, 6, 7 of HLA-Cw gene located outside of the routine testing region and its application in clinical matching / 中华检验医学杂志

Objective To study the molecular genetic polymorphism of exons 1,5, 6, 7 of HLA-C gene in Chinese population and evaluate the significance of additional sequencing based typing at exons 1,5, 6, 7 of HLA-Cw gene in clinical HLA matching, Methods A total of 324 individuals were typed at exons 2,3, 4 of HLA-C gene by sequence-based typing. If ambiguities appeared outside of exons 2 -4, we designed a total of 5 in-house sequencing primers and optimized the sequencing reaction, additional sequencing based typing at exons 1,5, 6, 7 was performed to solove the emerging ambiguities. Results In the three hundred and twenty-four samples typed by PCR-SBT at exons 2, 3 and 4 of HLA-Cw gene, 23.8 % (77/324) of the typed samples were assigned the conclusive genotype in four digital level 76. 2% (247/324) of the typed samples were given with the ambiguous allele combination results, in which 73 kinds of ambiguous allele combinations were detected. Increasing the additional sequencing analysis at exons 1, 5, 6, 7 of HIA-C gene, ten frequent ambiguities including Cw* 030201/030202, Cw* 070201/0750, Cw* 040101/0409N/0430, Cw* 0403/0409N/0430, Cw* 080101/0822 could be distinguished. ConclusionsIncreasing the sequencing anlysis at exons 1, 5, 6 and 7 of HLA-Cw gene will help to make clear the ambiguous SBT results and also improve the accuracy of HLA-Cw typing. It shows important significance in clinical histoeompatibility matching.

Simultaneous mutations in exon and intron of a novel human leukocyte antigen-B*3818 allele revealed by genomic sequence analysis / 中华检验医学杂志

Objective To analysis the genomic sequence of a novel human leukocyte antigen (HLA)-B*3818 allele.Methods Full length genomic sequence of an unknown HLA-B allele was cloned,followed by bi-directional sequencing and the specificity of the antigen coded by this novel allele was defined by microcytotoxicity assay.The frequency and haplotype of this novel allele was acquired by population census and parentage analysis.Results The full length genomic sequence of this novel HLA-B*3818 allele with accession number FJ561482 differs from HLA-B*380201 by two nucleotide changes in exon 4 and intron 5,respectively.One change is located at nt 660 in exon 4 where C→A alternation,which results in an amino acid substitution from Asp(GAC)to Glu(GAA)at codon 196.This alternation is a new single nucleotide polymorphism compared with all other HLA-B alleles.Another is located at genomic position 2133 in intron 5(A→C).Except for this substitution,the intron sequences of HLA-B*3818 allele are identical to those of other HLA-B*38 alleles including HLA-B*380101,B*380201 and B*3814.The serological specificity of HLA-B*3818 is B38 and the frequency of this new allele is less than 0.000 5 in Chinese Han population.The parentage analysis showed the haplotype of novel allele is A*030101-Cw*010201-B*3818-DRB1*1312-DOB1*060101.Conclusion The simultaneous mutations in exon and intron were found in the Hovel HLA-B*3818 allele,and so it can present more sequence information for studies and applications associated with HIA genes by analyzing the genomic sequences of novel HLA alleles.

Application of heterozygous ambiguity resolution primers resolving ambiguous genotyping results of human leukocyte antigen genes / 中华检验医学杂志

Objective To evaluate the heterozygous ambiguity resolution primers (HARPs) method in resolving ambiguous genotyping results of human leukocyte antigen (HLA) genes in Chinese Hart population, and choose some appropriate HARPs primers. Methods HLA-A, HLA-B and HLA-DRB1 genes of 416 southern Chinese Han individuals were genotyped by sequence-based-typing(SBT) method and then the ambiguous genotyping samples were sequenced again by HARPs primers provided by American Atria company. Results The percentage of ambiguous genotyping samples resolved by HARPs for HLA-A, HLA-B and HLA-DRBI locus was 86.3% (132/153), 73.9% (130/176) and 38.1% (85/223) respectively. Among them, 48.5% (64/132)HLA-A, 80.0% (104/130)HLA-B and all HLA-DRB1(85/85)samples only need one primer, 47.7 % (63/132)HLA-A and 20.0% (26/130)HLA-B samples need two primers. Three to six different HARPs primers can resolve more than 90% ambiguities. Conclusion HARPs is a convenient method and could be a routine method to resolve ambiguities for HLA-A, HLA-B and HLA-DRB1 genes genotyped by SBT in Chinese Han population.