HLA-DR and -DQ gene polymorphism in Latvian patients with insulin-dependent diabetes mellitus

Abstract: Latvian insulin-dependent diabetes mellitus (IDDM) patients ( n =101) and healthy controls ( n = 111) were analyzed for HLA-DR and DQ polymorphism. DR3-DQ2 and DR4-DQ8 were positively associated and DR15-DQ6, DR13-DQ6, DR1-DQ5 and DQ7 negatively associated with the disease. The incidence of LDDM in Latvia is very low (6.5 per 100,000) compared to Sweden (24.4 per 100,000), even though Latvia is close to Sweden. The reasons for the decreased incidence are not clear. When the negatively associated DQ were taken together in the healthy controls, more than 75% of the healthy controls were positive for one of the four negatively associated DQ molecules. The excess frequency of the negatively associated DQ molecules in the general population could explain the lower incidence of IDDM in Latvia. Association of HLA-DR and DQ genes with autoantibody markers shows DR3, but not DQ2, to be increased in GAD65 antibody-positive compared to antibody-negative patients. This association was not observed with ICA512 antibodies.     

西双版纳傣族及上海汉族群体HLA－DR2相关的DR／DQ单倍型分析

对４４名西双版纳傣族和９名上海地区汉族ＤＫ２阳性个体进行了与其相关的ＤＲ／ＤＱ单倍型组合的分析。傣族群体中ＤＲＢＩ－ＤＲ２亚型分布以＊１６０２与＊１５０２为最常见，其等位基因频率分别为４３．６％与，４０．０％和汉族群体中以＊１５０１为主明显不同。傣族群体中共检出１０种与ＤＲ２相关联的ＤＲ／ＤＱ单倍型；最常见的是ＤＲＢ１＊１６０２、ＤＲＢ５＊０１０１、ＤＱＡ１＊０１０２、ＤＱＢ１＊０５０２（３４．５％）与汉族及其他群体明显不同，本研究表明傣族不仅具有高频率的ＤＲ２，而且与ＤＲ２相关联的ＤＲＢ１、ＤＲＢ５、ＤＱＡ１、ＤＱＢ１单倍型组合有其独特性。     

HLA-DRB1 and DQB1 genotypes in patients with insulin-dependent neonatal diabetes mellitus. A study of 13 cases

Insulin-dependent neonatal diabetes mellitus (NDM) is a rare form of diabetes with a heterogeneous genetic background. The HLA-DRB1 and DQB1 genotypes were determined for 13 patients with NDM, from 9 unrelated families. Four patients had permanent NDM (PNDM) and 9 patients had transient NDM (TNDM). No excess of HLA susceptibility markers for type 1 diabetes (IDDM) was observed in this series of patients, whatever the forms of diabetes PNDM or TNDM. Paternal isodisomy of chromosome 6 was observed in two TNDM cases. These observations are consistent with the current hypothesis that there is a recessive susceptibility gene, at least in the transient form of the disease, unlinked to the MHC locus on chromosome 6. Although established in a short series, our results do not support an additive role of IDDM1 in the progression of the disease.     

HLA-DP polymorphism in Sudanese controls and patients with insulin-dependent diabetes mellitus

Human leukocyte antigen (HLA) genes are candidates for susceptibility to insulin-dependent diabetes mellitus (IDDM). The association of IDDM with particular DR and DQ alleles has been reported in all populations studied, but its association with HLA-DP alleles has been controversial. To address this question we analyzed 19 DPB1 and 2 DPA1 alleles and their associations in well-characterized Sudanese (an admixture of Arab and Black) IDDM patients (n = 71) and ethnically matched controls (n = 86) using polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) typing. There were no significant differences between the patient and control groups in the DPB1 frequencies. DPB1*0201, *0401 and DPA1*01 were the most frequent alleles in both IDDM patients and control subjects. Significant positive and negative associations between DPB1 and DPA1 alleles were detected in both groups. A novel DPB1 allele included in DPB1*1701 was identified.     

DQA1 restriction fragment length polymorphisms and insulin-dependent diabetes mellitus: A Bg1II fragment labels a subset of B8,DR3 haplotypes uniquely associated with insulin-dependent diabetes mellitus

Class II restriction fragment length polymorphism studies of 38 pedigrees with multiple cases of insulin-dependent diabetes mellitus revealed the existence of a DQA1-related polymorphism that distinguishes two kinds of HLA-B8,DR3 haplotypes. One of these, characterized by the presence of DQA1-BglII 7.20 kb, was present in all 14 examples inherited by patients and in 6 of the 12 B8,DR3 haplotypes not so inherited. The apparently complete association between the presence of this fragment and the "affected" status of B8,DR3 haplotypes (p = 0.004) was confirmed in a separate group of 26 simplex pedigrees selected for the presence of this haplotype in the respective probands (combined p less than 0.0001).     

TNFB gene polymorphism in insulin-dependent diabetes mellitus: association with HLA-DR alleles

A polymorphism of the TNF-β gene can be detected by restriction digestion of a PCR product with NcoI. In this study we look at the risk associated with this polymorphism in a study of 69 insulin-dependent diabetes patients and 119 healthy controls. The risk was further characterized by comparison to the HLA type of the individual, since the TNF polymorphism is in linkage disequilibrium with HLA genes.     

The Dai minority population of Southwest China: Heterogeneity of DR2-Associated HLA-DRB1,DRB5, DQA1, and DQB1 haplotypes

HLA-DR2 is the most common DR specificity (60.3%) identified in the Dai minority population of Xishuangbanna, Yunna Province, China. We characterized the DRB1, DRB5, DQA1, and DQB1 alleles of 44 unrelated DR2-positive individuals, 11 of whom (15%) were DR2 homozygous. Four DRB1 and four DRB5 alleles encoding DR2 were identified in this population. The most frequent DR2-associated DRB1 alleles were *1602 (gf = 0.164) and *1502 (gf = 0.151). DRB1*1501 (gf = 0.048) and a new allele designated DRB1*1504 (gf = 0.014) were also detected, but *1601 and *1503 were absent. The most frequent DR2-associated DRB5 alleles were *0101 (gf = 0.233) and *0102 (gf = 0.110). Nine different DR2-associated DR/DQ haplotypes were identified. The two most common DR2 haplotypes were DRB1*1602,DRB5*0101,DQA1*0102,DQB1*0502(hf = 0.142) and DRB1*1502,DRB5*0102,DQA1*0101, DQB1*0501 (hf = 0.075). The new DRB1*1504 allele was found on a single haplotype: DRB1*1504, DRB5*0101,DQA1*0102,DQB1*0502 (hf = 0.017). The Dw2, Dw12, Dw21, and Dw22 haplotypes, present in many other Asian and Mongoloid populations, were not identified in this unique group. However, the Dai minority population is characterized by a relatively large number of diverse DR2 haplotypes and a new DRB1 allele encoding DR2.     

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.     

IDDM与HLA-DQA1及其启动子QAP 的相关性研究

目的 研究胰岛素依赖性糖尿病（IDDM）的易感性与HLA－DQA1及其启动子QAP基因多态性是否存在关联。方法 采用PCR－RFLP分析DQA1等位基因多态性;采用PCR－SSO检测QAP多态性。结果 等位基因分析发现,患者中DQA1＊0301、QAP3．2等位基因频率显著高于正常人（RR＝2．80、2．43,P＜0．01）;而DQA1＊0601、QAP4．2在患者中分布频率较正常人显著降低（RR＝0．10,P＜0．025）。启动子与结构基因连锁分析表明：QAP3．2－DQA1＊0301单元型与IDDM关联,QAP3．1－DQA1＊0301与IDDM无关联;QAP4．20－DQA1＊0601则具有保护作用。结论 1．IDDM与HLA的关联不仅存在于结构基因,而且也存在于启动子;2．同一结构基因与不同的启动子连锁可呈现不同的关联格局。     

HLA DQA, DQB, and DRB genotyping by oligonucleotide analysis: distribution of alleles and haplotypes in British caucasoids.

A precise method for comprehensive HLA DQA and DQB genotyping using gene amplification and hybridization with sequence-specific oligonucleotide (SSO) probes is described. Twenty-four SSO probes were used to detect all DQ allotypes defined by nucleotide sequence variation in the second exons of the DQ genes, using a standard set of conditions for all probes at each locus. Five hundred individuals were genotyped for 8 DQA1 and 16 DQB1 alleles by using this method and for 33 alleles of the DRB1, DRB3, DRB4, and DRB5 genes by using previously described SSO probes. The 4-locus DQB1-DQA1-DRB1-DRB3/4/5 haplotypes present were characterized on the basis of known linkage disequilibrium between class II alleles. Fifty-two different haplotypes that have previously been described were further characterized at the nucleotide sequence level and two novel haplotypes were identified. The distributions of these alleles and haplotypes in 177 randomly selected healthy Caucasoid controls from the United Kingdom are reported. These results identify further haplotypic diversity in the HLA class II region, even though strong linkage disequilibrium exists between the DR and DQ gene loci.     

DNA typing of HLA-DQ alleles by gene amplification of DQA and DQB variable exons: analysis of DQA/DQB haplotypes.

In the present report, we describe a DNA typing method that allows detection of all the polymorphic variants of DQA1 and DQB1 second exons. By the oligotyping procedure provided in this paper, we are able to identify 8 DQA1 and 13 DQB1 alleles and to type random individuals in any heterozygous combination. We provide the hybridization and washing temperatures for using either 32P labelled or non-radioactive probes. The discrimination power of this procedure, compared to serological and cellular techniques, is remarkable. Therefore, this typing method finds perfect application in transplantation immunology and it will be very helpful to optimize the matching of unrelated donors before BMT. It is apparent from our results that despite the linkage disequilibrium present between DQ and DR loci, a DR specificity may frequently be associated to different DQ haplotypes. This is the case for DR4, DR7, DR8, DR9, and DR13 specificities.     

HLA DRB1, DQB1 and insulin promoter VNTR polymorphisms: interactions and the association with adult-onset diabetes mellitus in Czech patients

Both the human leucocyte antigen (HLA) DRB1 and the HLA DQB1 gene loci play a role in the development and progression of autoimmune diabetes mellitus (T1DM). Similarly, the insulin promoter variable number tandem repeats (INS-VNTR) polymorphism is also involved in the pathogenesis of diabetes mellitus (DM). We studied the association between each of these polymorphisms and DM diagnosed in patients older than age 35 years. Furthermore, we analysed possible interactions between HLA DRB1/DQB1 and INS-VNTR polymorphisms. Based on C-peptide and GADA levels we were able to distinguish three types of diabetes: T1DM, latent autoimmune diabetes in adults (LADA) and T2DM. INS-VNTR was genotyped indirectly by typing INS-23HphI A/T polymorphism. The genotype and allele frequencies of INS-23HphI did not differ between each of the diabetic groups and group of healthy subjects. We did, however, observe an association between the INS-23HphI alleles, genotypes and C-peptide secretion in all diabetic patients: A allele frequency was 86.2% in the C-peptide-negative group vs. 65.4% in the C-peptide-positive group (P(corr.) < 0.005); AA genotype was found to be 72.4% in the C-peptide-negative group vs. 42.6% in the C-peptide-positive groups (P(corr.) < 0.01). The HLA genotyping revealed a significantly higher frequency of HLA DRB1*03 allele in both T1DM and LADA groups when compared to healthy subjects: T1DM (25.7%) vs. control group (10.15%), odds ratio (OR) = 3.06, P < 0.05; LADA (27.6%) vs. control (10.15%), OR = 3.37, P < 0.01. The simultaneous presence of both HLA DRB1*04 and INS-23HphI AA genotype was detected in 37.5% of the T1DM group compared to only 9.2% of the healthy individuals group (OR = 5.9, P(corr.) < 0.007). We summarize that in the Central Bohemian population of the Czech Republic, the INS-23HphI A allele appears to be associated with a decrease in pancreatic beta cell secretory activity. HLA genotyping points to at least a partial difference in mechanism, which leads to T1DM and LADA development as well as a more diverse genetic predisposition in juvenile- and adult-onset diabetes. The simultaneous effect of HLA and INS-VNTR alleles/genotypes predispose individuals to an increased risk of diabetes development.     

HLA-DR2 in two sibships with insulin-dependent diabetes mellitus.

We report two families selected from 124 genotyped Caucasian insulin-dependent diabetes mellitus (IDDM) families because of unusual features. In both families, all offspring are affected and four out of six bear the allele HLA-DR2 which is an uncommon phenotype among diabetic patients. Onset before the age of 1 year in all the patients of one family, association with optic atrophy in the other, and the existence of pairs of affected sibs of different HLA types in both, are infrequent findings and support the evidence of heterogeneity in IDDM.     

An investigation of Japanese subjects maps susceptibility to type 1 (insulin-dependent) diabetes mellitus close to the DQA1 gene.

Insulin-dependent diabetic and control subjects of Japanese origin were HLA-DRB1, -DQB1, and -DQA1 typed using restriction fragment length polymorphism analysis and sequence-specific oligonucleotide gene probing. The DQA1 allele DQA1*0301 was positively associated with the disease [48/52 (92%) diabetic patients versus 44/64 (69%) control subjects, Pc less than 0.03, RR = 4.97]. Alleles of the DRB1 and DQB1 genes showed no significant association with the disease. The frequency of DQB1 genotypes encoding the amino acid aspartic acid at position 57 of the DQ beta chain did not differ significantly between subjects with insulin-dependent diabetes mellitus (IDDM) and controls. These findings suggest that a susceptibility allele for IDDM in the Japanese is more closely associated with the DQA1 gene than the DQB1 gene.     

HLA-A, B, DR antigens and insulin-dependent diabetes in Algerians

HLA-A, B and DR antigens have been investigated in insulin-dependent diabetics and compared to controls in a population of Algerians. A decrease of A1 and DR2 and an increase of Aw 19.2; B8, B18 and especially DR3 were found in diabetics in comparison to controls. The strongest association was found for DR3, which is a good genetic marker of IDD (RR = 8.50) in this population. The frequency of some HLA antigen associations in IDD suggests that the diabetic gene(s) is linked to 2 main haplotypes: Aw 19.2; B18; DR3 and Aw 19.2; B8; DR3. Antigen DR4 was equally represented in IDD (21%) and controls (28.4%), but heterozygote DR3-DR4 was more frequent in diabetics. The relation between IDD and HLA antigens found in the Algerian population is very similar to that described in diabetic Caucasian populations of southern Europe, except for the lack of association with DR4.