HLA-DRB1, DQA1, DQB1 DNA polymorphism in the Bulgarian population

We describe for the first time the use of PCR based techniques to analyze the MHC class II polymorphism of the Bulgarian population. The present study provides the HLA-DRB, DQB1 allele frequencies in 116 Bulgarian individuals and DQA1 alleles frequencies in 100 subjects. DNA from these individuals was typed for DRB and DQB1 typed by the PCR- Allele Specific Amplification (PCR-ASA) method and DQA1 by PCR followed by hybridization using Sequence Specific Oligonucleotides (PCR-SSO). Allele and haplo-type frequencies and linkage disequilibria are computed by the standard methods used for the XIth International Histocompatibility Workshop. The highest frequencies are 0.159, 0.109 and 0.085 for DRB1*1101, DRB1*1601 and DRB1*1301 respectively. Among the eight DQA1 alleles detected, DQA1*0501 (0.344) is found to be much more frequent than the two most frequent alleles DQA1*0102 (0.225) and DQA1*0101 (0.151). Twelve DQB1 alleles are found and three of them, DQB1*0301 (0.280), DQB1*0502 (0.153) and DQB1*0201 (0.133) showed the highest frequencies. The haplo-type DRB1*1101-DQA1*0501-DQB1*0301 (0.079) predominate clearly, followed by DRB1*1601-DQA1*0102-DDQB1*0502 (0.055) and DRB1*0101-DQA1*0101-DQB1*0501. These results indicate that the Bulgarian population is characterized by features representative of the European anthropological type with a substantial contribution from the Southern Belt of Europe.     

Molecular analysis of HLA-DRB1, DQA1, DQB1, DQ promoter polymorphism and extended class I/class II haplotypes in the Seri Indians from Northwest Mexico

The study of the genetics of the Major Histocompatibility Complex (MHC) in Amerindians is of great value in understanding the origins and migrations of these native groups, as well as the impact of immunogenetics on the epidemiology of diseases affecting these populations. We analyzed, using Polymerase Chain Reaction and Sequence Specific Oligonucleotide Probes (PCR-SSOP), DRB1, DQA1, DQB1 alleles and the promoter regions of DQA1 and DQB1 genes in 31 unrelated and 24 related Seri, a Mexican Indian group, from the state of Sonora (Northwest Mexico). The class II genotypes of this population were found to be in genetic equilibrium. The allele frequency (AF) of the prevalent DRB1 alleles were DRB1*0407 (48.4%), DRB1*0802 (33.9%) and DRB1*1402 (16.1%). The most frequent DQA1 and DQB1 alleles were DQA1*03011 (AF = 50.00%), DQA1*0401 (AF = 33.87%) and DQA1*0501 (AF = 16.13%); DQB1*0302 (AF = 50.00%), DQB1*0402 (33.87%) and DQB1*0301 (16.13%); which were in combination with DRB1*0407, DRB1*0802 and DRB1*1402, respectively. Three QAP and three QBP alleles were present (QAP 3.1, 4.1, 4.2; QBP 3.1, 3.21, 4.1) associated with the typical published DQA1 and DQB1 alleles. Four class II haplotypes were present in family members: DRB1*0407-QAP-3.1-DQA1*03011-QBP-3.21-DQB1*0302; DRB1*0802-QAP-4.2-DQA1*0401-QBP-4.1-DQB1*0402; DRB1*1402-QAP-4.1-DQA1*0501-QBP-3.1-DQB1*0301 and DRB1*0701-QAP-2.1-DQA1*0201-QBP-2.1-DQB1*0201. The family data were used to confirm extended haplotypes. A total of 21 haplotypes were found when A* and B* loci were also considered. The three most frequent combinations included A*0201-B*3501-DRB1*0407, A*3101-B*5101-DRB1*0802, and A*0201-B*40-DRB1*1402.     

Expression of HLA‐DQA1 and HLA‐DQB1 genes in B lymphocytes,monocytes and whole blood

Differential expression of HLA‐DQA1 and HLA‐DQB1 gene alleles was analysed in three different cell populations isolated from peripheral blood—B lymphocytes, monocytes and whole‐blood cells. Interallelic differences in mRNA levels were observed: DQA1*03 alleles were among the most expressed in all cell types, whereas DQA1*05 alleles were least expressed in whole blood and monocytes and among the most expressed in B cells. For DQB1 gene, DQB1*06 group of alleles were the most expressed, and DQB1*02 group the least expressed within all cell populations examined. In comparison with the rest alleles, DQB1*06 and DQB1*05:02 alleles have higher expression in monocytes than in B cells, professional antigen‐presenting cells. Cell type‐specific regulation of expression was observed as well, with higher and more balanced expression of alleles in B lymphocytes compared to monocytes.     

Highly polymorphic promoter regions of HLA DQA1 and DQB1 genes do not help to further define disease susceptibility in insulin-dependent diabetes mellitus

HLA DQA1, HLA DQB1 genes confer susceptibility to insulin-dependent (type 1) diabetes mellitus (IDDM). Since variants of their upstream regulatory regions are linked to the exons, we investigated their promoter polymorphisms (QAP and QBP) by a combination of PCR-based typing protocols in 136 IDDM patients, 167 controls and 6 families with an IDDM proband to identify possible additional susceptibility markers. Of major interest for IDDM susceptibility are the promoter "splits" of HLA DQA1*0301 (QAP3.1 and QAP3.2) and HLA DQB1*0302 (QBP3.2 and QBP3.3). QAP 3.1 (96% in patients vs 98% in controls) and QBP3.2 (100% vs 99%) were found to be the most frequent promoter variants for HLA DQA1*0301 and DQB1*0302, respectively, whereas QAP3.2 and QBP3.3 were very rare. Furthermore the promoter "splits" were equally distributed on the respective exon alleles in all groups and cosegregated in families as expected. In conclusion, HLA DQ-mediated susceptibility and protection in IDDM is not restricted to the exon but extends to the promoter region without further defining the genetic risk.     

抗磷脂抗体阳性SLE患者HLA DRB1、DQA1、DQB1基因单倍型研究

本文采用ＰＣＲ ＲＦＬＰ技术对抗磷脂抗体阳性（ＡＰＡ＋）ＳＬＥ患者ＨＬＡ ＤＲＢ１、ＤＱＡ１ 和ＤＱＢ１ 基因进行分型研究, 同时以上海地区汉族随机人群作对照, 发现这类病人的ＤＲＢ１＊ ０８０３ ＤＱＡ１＊ ０１０３ ＤＱＢ１ ＊０６０１ 单倍型频率显著增高（ Ｐ＜ ０－０１） 相对危险率为４－４５, 说明该疾病与此单倍型存在着很强的关联。     

HLA-DRB1、DQB1基因与汉族人群寻常型天疱疮的相关性研究

目的　探讨 HL A- DRB1、DQB1位点基因在汉族人群寻常型天疱疮易感性中的作用。方法用序列特异性引物 -聚合酶链反应方法 ,对 6 1例寻常型天疱疮 (pemphigus vulgaris,PV)患者和 5 7名正常对照进行了 HL A- DRB1、DQB1等位基因的分型 ,并分析了 DRB1、DQB1基因在两组中的分布。结果　与正常对照组比较 ,PV组 DR4、DRB1* 14 (* 14 0 1、* 14 0 4、* 14 0 5 )基因频率明显增高 (Pc分别 <0 .0 5及P<0 .0 1) ,差异有显著性 ;PV组 DQB1* 0 5 0 3、DQB1* 0 30 2基因频率明显增高 (Pc均 <0 .0 5 ) ,差异有显著性。对 DR4阳性样本的组内基因亚型分型结果发现 ,PV组中 DRB1* 0 4 0 3、DRB1* 0 4 0 6频率显著增高(Pc<0 .0 5 ) ,差异有显著性。 PV患者组单倍型 HL A- DRB1* 0 4 ,DQB1* 0 30 2和 HL A- DRB1* 14 ,DQB1* 0 5 0 3频率明显增高 (P<0 .0 5 )。结论　HL A- DRB1* 0 4 ,DQB1* 0 30 2和 HL A- DRB1* 14 ,DQB1* 0 5 0 3可能是汉族人 PV推测的易感单倍型。     

HLA-DRB1, -DQA1 and -DQB1 genotyping of 180 Czech individuals from the Czech Republic pop 3

One hundred and eighty Czech individuals from the Czech Republic pop 3 were genotyped at the HLA-DRB1, -DQA1 and -DQB1 loci using sequence-specific primers PCR methods. HLA-DRB1, -DQA1 and -DQB1 genotypes are consistent with expected Hardy–Weinberg (HW) proportions. These genotype data are available in the Allele Frequencies Net Database under identifier AFND.     

用PCR-SSP方法研究广西壮族HLA-DQA1和B1基因多态性

目的　检测广西壮族ＨＬＡＤＱＡ１ ,Ｂ１ 基因的多态性。方法　应用ＰＣＲＳＳＰ 方法对１４０ 名健康、无血缘关系广西壮族人的ＨＬＡＤＱＡ１ 和ＤＱＢ１ 进行基因分型。结果　共检出７ 个ＤＱＡ１ 等位基因和１６ 个ＤＱＢ１ 等位基因。在检出的ＤＱＡ１ 等位基因中,０３０１ 的基因频率最高（３５ ％ ） ,０４０１ 的基因频率最低（１ ．１ ％ ） 。在ＤＱＢ１ 等位基因中,０６０１（２２ ．１ ％ ） ,０３０１（２０ ．７ ％ ） ,０５０１（１３ ．９ ％ ） 最为常见。未检出的等位基因包括ＨＬＡＤＱＡ１ ＊ ０２０１ ,０３０２ ,０６０１ ,ＤＱＢ１ ＊ ０６０３ ,０６０５ 和０６０８ 。结论　广西壮族ＨＬＡＤＱＡ１ ,Ｂ１ 基因的多态性不仅有中华民族的特点,而且也有其独特性。     

北方汉族HLA-DRB1、DQB1基因多态性的研究

目的从基因水平了解北方汉族ＨＬＡ－ＤＲＢ１、ＤＱＢ１多态性分布,获得更完整、更准确的遗传学数据。方法应用ＰＣＲ－ＳＳＰ方法对１０７名北方汉族健康人进行了ＨＬＡ－ＤＲＢ１、ＤＱＢ１等位基因分型。结果鉴定了１４个ＤＲＢ１等位基因,９个ＤＱＢ１等位基因,包括了ＤＲ、ＤＱ位点的全部血清学特异性。结论提供了一套比较完整准确的ＤＲＢ１、ＤＱＢ１等位基因的基因频率和连锁不平衡参数。对群体遗传和疾病关联的研究具有重要的意义。     

HLA class IIDRB, DQA1 and DQB1 polymorphisms in the Polish population from Wielkopolska

HLA DRB1, DQA1 and DQB1 alleles were determined by DNA PCR-SSO typing in a sample of 99 individuals originating from Wielkopolska (midwestern Poland). A high number of alleles (38 DRB1, 8 DQA1 and 14 DQB1) was detected at each locus, many of them presenting notable frequencies in this population. The three HLA loci are thus characterized by very high heterozygosity levels (93% for DRB1, 85% for DQA1, and 88% for DQB1), which confirms the results found for other European populations. A total of 6 DRB1-DQA1-DQB1 haplotypes are detected with an estimated frequency higher than 5%, namely, DRB1*1501-DQA1*0102-DQB1*0602, DRB1*0701-DQA1*0201-DQB1*0201, DRB1*0101-DQA1*0101-DQB1*0501, DRB1*1101-DQA1*0501-DQB1*0301, DRB1*03011-DQA1*0501-DQB1*0201, and DRB1*1301-DQA1*0103-DQB1*0603. A genetic distance analysis between the Polish and other world populations tested for HLA class II indicates that the Wielkopolska community is close to geographically close, rather than linguistically related populations from Europe. More generally, a good agreement between genetics and geography is found for DRB1 and DQB1 polymorphisms in Europe, suggesting that these two loci are highly informative for assessing historical relationships among humans.     

The HLA DQB 1*0502 allele is neutrally associated with insulin-dependent diabetes mellitus in the Sardinian population

In the Sardinian population a very high incidence of insulin-dependent diabetes mellitus (IDDM) and the lack of HLA-DR2 protective effect due to the high frequency of the A2, Cw7, B17, 3F31, DR2, DQw1 extended haplotype has been reported. This haplotype, carrying a Serine at position 57 of the DQB1*0502 allele, has been previously reported to be underrepresented in patients when compared to controls. In order to provide an explanation for this finding, we defined by RFLP analysis the HLA haplotype of 45 Sardinian IDDM patients and 49 controls. All DR-2DQw1 subjects were molecularly characterized at the HLA DQA and DQB loci. All DR2-positive patients and the vast majority of the DR2-positive controls had the DQB1*0502 allele at the DR2-linked DQB1 locus, with no statistically significant difference between the two groups. All DQA1 genes were the ones expected, with only two exceptions. Nine out of 10 of the DR2-positive patients were compound heterozygotes for DQB1*0201/DQB1*0502 alleles; only this allele combination was significantly increased (p less than 0.0003). Our data suggests that a) the DQB1*0502 allele is neutral for IDDM development and b) the susceptibility to IDDM in our DR2-positive patients is related to the compound heterozygous state between the neutral DQA1*0102/DQB1*0502 and the susceptibility DQA1*0501/DQB1*0201 alleles.     

HLA-DRB1 and DQB1 polymorphisms in southern France and genetic relationships with other Mediterranean populations

This study presents the results of HLA-DRB1 and DQB1 sequence-specific oligonucleotide probe (SSOP) typing for a population sample of 181 individuals originating from southern France. On the basis of allele and haplotype frequencies, we compared our population with others from the Mediterranean area. Allele frequencies are comparable to those found in other western European populations (France, Portugal, Spain) and indicate neighboring exchanges. The haplotype frequencies showed relationships with North Africans and Jewish populations, as well as the common origin of Moroccan and Lebanese Jews. Therefore, allele frequencies seem to be more able to show recent exchanges while haplotype frequencies might show ancestral relationships. These results may serve as references for future studies of HLA and disease in southern France.     

Identification by sequencing based typing and complete coding region analysis of three new HLA class II alleles: DRB3*0210, DRB3*0211 and DQB1*0310

The study of HLA class II polymorphism by direct exon 2 DNA sequencing analysis has been established to be a reliable and accurate high-resolution typing procedure. This approach shows some advantages in relation to previous methods, polymerase chain reaction using sequence-specific oligonucleotides (PCR-SSO) and sequence-specific primers (PCR-SSP), basically due to the capability of analysis for the complete sequenced genomic region, including non-polymorphic motifs. DRB3 and DQB1 sequencing based typing (SBT) in unrelated bone marrow donor searching allowed us to detect three new alleles. The complete coding region sequences were characterised from cDNA. Two new DRB3 alleles, DRB3*0210 and DRB3*0211, were described in two Caucasian bone marrow donors. Both sequences showed single point mutations regarding DRB3*0202, producing amino acid replacements at positions 51 (Asp to Thr) and 67 (Leu to Ile), respectively. These two point mutations can be found in other DRB alleles, and suggest that gene conversion would be involved in the origin of both alleles. A new DQB1 sequence was found in a Spanish patient that showed two nucleotide differences, positions 134 and 141, with regard to its close similar DQB1*03011 allele. Only substitution at position 134 provoked amino acid replacement at residue 45, Glu to Gly. This single amino acid change would be involved in the lack of serologic recognition of this new molecule by DQ7-specific reagents.     

HLA-DRB1, DQB1 and DPB1 polymorphism in the Naxi ethnic group of South-western China

Polymorphism of HLA-DRB1, DQB1 and DPB1 was revealed with a sequencing-based typing (SBT) method in unrelated healthy volunteers from the Naxi ethnic group. Among the 43 DRB1 alleles detected, the most common allele was DRB1*12021 with a frequency of 17%, followed by DRB1*08032, DRB1*09012 and DRB1*1404 with frequencies of 8.5%, 7.4% and 7.4%, respectively. Among 23 DQB1 alleles detected, the most frequent DQB1 allele was DQB1*03011/0309 (21.9%), followed by DQB1*0502 (16.4%) and DQB1*05031 (9.6%). For the DPB1 locus, the most common alleles were DPB1*0501 (25.5%), DPB1*0402 (14.6%) and DPB1*02012 (12.0%). The most common DRB1-DQB1-DPB1 haplotype was DRB1*1404-DQB1*05031-DPB1*0402 with a frequency of 5.26%, followed by the DRB1*08032-DQB1*06011-DPB1*1301 (3.51%). The distribution characteristics of the HLA class II alleles revealed that the Naxi ethnic group belonged to the Southern group of Chinese.     

HLA-DRB1, -DQA1, -DQB1, -DPA1 and -DPB1 genes in Japanese multiple sclerosis patients

Japanese MS patients and controls were examined for the distribution of HLA-DRB1, -DQA1, -DQB1, -DPA1 and -DPB1 alleles using in vitro amplification of genomic DNA and probing with sequence-specific oligonucleotides. No significant difference in frequency of the examined alleles was observed among the two groups. This is in contrast to Norwegian MS patients, where an association to a combination of certain DQA1 and DQB1 alleles has previously been demonstrated.     

DNA methylation and mRNA expression of HLA‐DQA1 alleles in type 1 diabetes mellitus

Type 1 diabetes (T1D) belongs among polygenic multifactorial autoimmune diseases. The highest risk is associated with human leucocyte antigen (HLA) class II genes, including HLA‐DQA1 gene. Our aim was to investigate DNA methylation of HLA‐DQA1 promoter alleles (QAP) and correlate methylation status with individual HLA‐DQA1 allele expression of patients with T1D and healthy controls. DNA methylation is one of the epigenetic modifications that regulate gene expression and is known to be shaped by the environment.Sixty one patients with T1D and 39 healthy controls were involved in this study. Isolated DNA was treated with sodium bisulphite and HLA‐DQA1 promoter sequence was amplified using nested PCR. After sequencing, DNA methylation of HLA‐DQA1 promoter alleles was analysed. Individual mRNA HLA‐DQA1 relative allele expression was assessed using two different endogenous controls (PPIA, DRA). We have found statistically significant differences in HLA‐DQA1 allele 02:01 expression (PPIA normalization, P_corr = 0·041; DRA normalization, P_corr = 0·052) between healthy controls and patients with T1D. The complete methylation profile of the HLA‐DQA1 promoter was gained with the most methylated allele DQA1*02:01 and the least methylated DQA1*05:01 in both studied groups. Methylation profile observed in patients with T1D and healthy controls was similar, and no correlation between HLA‐DQA1 allele expression and DNA methylation was found. Although we have not proved significant methylation differences between the two groups, detailed DNA methylation status and its correlation with expression of each HLA‐DQA1 allele in patients with T1D have been described for the first time.     

HLA class II DNA polymorphism in a Moroccan population from the Souss, Agadir area

Abstract: HLA DRB1, DQA1 and DQB1 polymorphisms were analyzed by PCR-SSO typing in a sample of the Moroccan population from Souss. Uneven allelic frequency distributions are observed at each locus, with particularly high frequencies for DRB1*0701, DRB1*0301, DQA1*0501, DQA1*0201, and DQB1*0201. Only three haplotypes (DRB1*0701-DQA1*0201-DQB1*0201, DRB1*0301-DQA1*0501-DQB1*0201 and DRB1*11-DQA1*0501-DQB1*0301) account for nearly 50% of the total gene frequencies. A genetic distance analysis reveals that the Moroccan population is close to the Spanish and the Algerians, who live in geographically neighboring areas. However, the Souss population is also characterized by a lower level of genetic diversity compared to other African and European populations from the Mediterranean area. This may be the result of a rapid genetic drift due to their likely geographical and/or cultural isolation.     

云南昆明白族、汉族、彝族儿童HLA—DQA 1等位基因多态性分析

为了解昆明白族、汉族、彝族儿童HLA-DQA1等位基因多态性.采用PCR-SSP技术对昆明地区无血缘关系的3个民族儿童的HLA-DQA1等位基因进行分析.结果显示3个民族儿童HLA-DQA1基因位点上共检出14种等位基因.其中昆明白族儿童HLA-DQA1最常见的等位基因为＊0601（16.67%）,高频等位基因为＊0103、＊0102、＊0303;昆明汉族儿童HLA-DQA1最常见的等位基因为＊0302（26.67%）,高频等位基因为＊0103、＊0601;昆明彝族儿童HLA-DQA1最常见的等位基因为＊0601（38.57%）,除＊0601外没有高频等位基因,余基因频率均小余10%,同时在基因排序上3个民族也存在着差异.结果提示,昆明地区3个民族儿童HLA-DQA1基因分布既有共同特点,又有其独特性.     

Extensive HLA class II studies in 58 non-DRB1*15 (DR2) narcoleptic patients with cataplexy

Narcolepsy is a sleep disorder that has been shown to be tightly associated with HLA DR15 (DR2). In this study, 58 non-DR15 patients with narco-lepsy-cataplexy were typed at the HLA DRB1, DQA1 and DQB1 loci. Subjects included both sporadic cases and narcoleptic probands from multiplex families. Additional markers studied in the class II region were the promoters of the DQA1 and DQB1 genes, two CA repeat polymorphisms (DQCAR and DQCARII) located between the DQA1 and DQB1 genes, three CA repeat markers (G51152, T16CAR and G411624R) located between DQB1 and DQB3 and polymorphisms at the DQB2 locus. Twenty-one (36%) of these 58 non-DR15 narcoleptic patients were DQA1*0T02 and DQBI*0602, a DQ1 Subtype normally associated with DRB1*15 in DR2-positive narcoleptic subjects. Additional microsatellite and DQA1 promoter diversity was found in some of these non-DR15 but DQB1*0602-positive haplotypes but the known allele specific codons of DQA1*0102 and DQB1*0602 were maintained in all 21 cases. The 37 non-DQA1*0102/DQB1*0602 subjects did not share any particular HLA DR or DQ alleles. We conclude that HLA DQA1*0102 and DQB1*0602 are the most likely primary candidate susceptibility genes for narcolepsy in the HLA class II region.