Genetic associations between ADHD and dopaminergic genes (<Emphasis Type="Italic">DAT1</Emphasis> and <Emphasis Type="Italic">DRD4</Emphasis>) VNTRs in Korean children

It is well known that dopaminergic genes affect the development of attention deficit hyperactivity disorder (ADHD) in various populations. Many studies have shown that variable number tandem repeats (VNTRs) located within the 3′-untranslated region of DAT1 and in exon 3 of DRD4 are associated with ADHD development; however, these results were inconsistent. Therefore, we investigated the genetic association between two VNTRs and ADHD in Korean children. We determined the VNTRs using PCR. We examined genotype and allele frequency differences between the experimental and control groups, along with the odds ratios, using Chi square and exact tests. We observed a significant association between the children with ADHD and the control group in the 10R/10R genotype of DAT1 VNTRs (p?=?0.025). In addition, the 11R allele of DAT1 VNTRs showed a higher frequency in the control group than in the ADHD group (p?=?0.023). Also, the short repeat (without 11R) and long repeat alleles (including 11R) were associated with ADHD (p?<?0.05). The analysis of DRD4 VNTRs revealed that the 2R allele is associated with ADHD (p?=?0.025). A significant result was also observed in long and short repeats (p?<?0.05). Additionally, ADHD subtypes showed that the DRD4 VNTRs are associated with combined and hyperactive-impulsive subtype groups (p?<?0.05). Therefore, our results suggest that DAT1 VNTRs and DRD4 VNTRs play a role in the genetic etiology of ADHD in Korean children.     

Polymorphism in promoter regions of matrix metalloproteinases (<Emphasis Type="Italic">MMP1</Emphasis>, <Emphasis Type="Italic">MMP9</Emphasis>, and <Emphasis Type="Italic">MMP12</Emphasis>) in chronic obstructive pulmonary disease patients

Our studies have shown that the genotype and allele frequencies of polymorphisms G(?1607)GG of MMP1 gene, C(?1562)T of MMP9 gene, and A(?82)G of MMP12 gene do not significantly differ in the samples of chronic obstructive pulmonary disease (COPD) patients (N = 318) and healthy controls (N = 319) dwelling in Bashkortostan Republic. However, association of (?1562)T allele of the MMP9 gene with the severity of COPD disease progression has been revealed. In COPD patients at stage 4 of the disease, the frequency of allele T was significantly higher that in patients with the stages 2 and 3 (15.89% versus 8.38%; χ² = 7.804; d.f. = 1; P = 0.005; OR = 2.06 95% CI 1.22–3.49). The distribution of the genotype frequencies of C(?1562)T polymorphism of MMP9 gene significantly differed between the patients with various COPD severity (χ² = 9.849; d.f. = 2; P = 0.007). The individuals with rare genotype TT were revealed only among patients with severe COPD form (3.97% versus 0%; χ² = 4.78; P = 0.029; P _cor = 0.058). Analysis of this polymorphism in patients with early COPD onset (younger than 55 years old) has shown a significant increase in the allele T frequency in the group of patients with severe COPD (stage 4 according to GOLD) compared to the patients of the same age but with less severe COPD progression (χ² = 5.26; d.f. = 1; P = 0.022). As the major clinical characteristics of stage 4 COPD is the development of pulmonary emphysema as well as bronchial walls deformation, we suggest that the increased expression of MMP9 gene caused by genetic polymorphism in the gene promoter is important in the early development of serious complications of the disease.     

Analysis of <Emphasis Type="Italic">ICAM1</Emphasis> gene polymorphism in Slovak multiple sclerosis patients

Infiltration of immune cells into CNS is one of the essential events in multiple sclerosis (MS) development. Adhesion molecules like the intercellular adhesion molecule 1 (ICAM-1) play critical role in this process. Therefore, the ICAM1 gene containing two important single-nucleotide polymorphisms (SNPs) belongs to candidate loci with possible involvement in MS susceptibility and/or severity. The objective of our case-control study was to analyze the association of two functional ICAM1 polymorphisms rs1799969 (or G241R) and rs5498 (or K469E) with susceptibility to MS and evaluate their influence on the age at disease onset, severity, neurological disability and progression rate. Two hundred forty-eight MS subjects (mean 39.2 years) and 208 age-matched controls (mean 35.6 years) were involved in the study. Genotyping of ICAM1 rs1799969 and rs5498 SNPs was performed by PCR-RFLP. Presence of the rs3135388 polymorphism tagging the major MS risk allele HLA-DRB1*15:01 allele was determined as well. Our analysis revealed no statistically significant association of ICAM1 polymorphisms with risk of MS development in the Slovak population. Stratification of study cohorts by gender, age at onset and presence of the HLA-DRB1*15:01 risk allele showed only moderate changes. Correlation of clinical findings as age at onset, Kurtzke Expanded Disability Status Scale, Multiple Sclerosis Severity Score and progression index with ICAM1 genotypes in MS patients revealed no significant association; however, patients with earlier onset of MS showed slightly higher frequencies of the homozygous G allele at rs5498 in comparison to other genotypes (P = 0.04), suggesting that GG carriers tend to induce MS at an earlier age.     

Association analysis of alcohol metabolizing enzymes <Emphasis Type="Italic">ADH1B,ADH7, CYP2E1</Emphasis> gene polymorphism with risk for coronary atherosclerosis

The allele and genotype distribution of two alcohol dehydrogenase genes ADH1B (exon 3 polymorphism A/G (47His)), ADH7 (intron 5 polymorphism G/C) and cytochrome P450 2E1 gene (CYP2E1; 5′-flanking region G/C and intron 6 T/A polymorphisms) were examined in Russian (Tomsk, n = 125) healthy population and in coronary atherosclerosis patients (CA, n = 92). The genotype frequencies followed the Hardy-Weinberg equilibrium and the alleles were in linkage equilibrium or gametic equilibrium in the control sample. Only two CYP2E1 gene polymorphisms were in linkage disequilibrium. The frequencies of the derived alleles at ADH1B ^* G (+MslI) allele, CYP2E1 ^* C2 (+PstI) allele and CYP2E1 ^* C (-DraI) allele were 8.48 ± 1.86, 1.20 ± 0.69, and 10.00 ± 1.90%, respectively. The ADH7 gene polymorphism showed a high level of heterozygosity; the frequency of the ADH7 ^* C (-StyI) allele was 44.58 ± 3.21%. A significantly higher frequency of CYP2E1 PstI C2 allele has been revealed in the CA group (P = 0.043; OR = 4.23; 95% CI 1.03–20.01). The tendency to significant effect of A1A2 genotype in ADH1B MslI polymorphism was observed for systolic blood pressure in the control group (P = 0.068). The statistically significant two-way interaction effects of ADH7 StyI and CYP2E1 DraI on diastolic blood pressure (P = 0.029) and on the serum high density lipoprotein level (P = 0.042) were also revealed. Association of A1A2 genotype in ADH1B MslI polymorphism with reduced amount in a serum of a very low density lipoprotein level (P = 0.045) have also been shown. This may result from multifunctional activity of alcohol metabolizing enzymes and their involvement in many metabolic and free radical reactions in the body.     

BrFLC5: a weak regulator of flowering time in <Emphasis Type="Italic">Brassica rapa</Emphasis>

Key message

A splicing site mutation in BrFLC5, a non-syntenic paralogue of FLOWERING LOCUS C, was demonstrated to be related to flowering time variation in Brassica rapa.

Abstract

Flowering time regulation in Brassica rapa is more complex than in Arabidopsis, as there are multiple paralogues of flowering time genes in B. rapa. Brassica rapa contains four FLOWERING LOCUS C (FLC) genes, three of which are syntenic orthologues of AtFLC, while BrFLC5 is not. BrFLC1, BrFLC2, and BrFLC3 have been reported to be involved in flowering time regulation. However, BrFLC5 has thus far been deemed a pseudogene. We detected two alternative splicing patterns of BrFLC5 resulting from a nucleotide mutation (G/A) at the first nucleotide of intron 3 (named as Pi3+1(G/A)). Genotyping of BrFLC5Pi3?+?1(G/A) for 301 B. rapa accessions showed that this single nucleotide polymorphism was significantly related to flowering time variation (p?<?0.001). In the collection, the frequency of the functional G allele (35.2%) was much lower than that of the nonfunctional A allele (59.1%); however, the frequency of the G allele was very high among the turnips (83.6%). An F2 population segregating at this locus was developed to analyze the genetic effect of BrFLC5. The result showed that the G allele individuals began to bolt two days later than the A allele individuals, indicating that BrFLC5 is a weak regulator of flowering time. BrFLC5 was expressed at the lowest level among the three analyzed BrFLCs. The late allele (G allele) was dominant to the early allele (A allele) at the BrFLC5 locus, which was in contrast to that of BrFLC1 and BrFLC2. This characteristic suggests that BrFLC5 would be more efficient for breeding premature bolting resistance in B. rapa.

     

Association between the length of the <Emphasis Type="Italic">MUC8-</Emphasis>minisatellite 5 region and susceptibility to chronic obstructive pulmonary disease (COPD)

In asthma and chronic obstructive pulmonary disease (COPD), mucins display disease-related alterations caused by airway mucus obstruction. MUC5AC, MUC5B and MUC8 are known as the major secretory mucins in human airway epithelial cells. Analysis of mucin genes has identified the presence of several features with a variable number of tandem repeats (VNTR; minisatellites) in the central region of each mucin. In our previous study, six minisatellites in the region of the MUC8 gene were identified, and the MUC8-MS5 minisatellite showed the highest heterozygosity among them. In this study, we evaluated the relationship between MUC8-MS5 and susceptibility to asthma and COPD. A case-control study was performed with 229 controls, 123 COPD cases and 77 asthma cases. A significant association (OR 3.96) between short alleles (2/2 repeats) and the occurrence of COPD was observed [95% confidence interval (CI) 1.32–11.88; p?=?0.008]. Hence, the increased frequency of 2/2 homo-short alleles were also found in asthma cases (3.11; CI 0.88–11.05; p?=?0.066), though this association was not statistically significant. These results revealed a genetic association between MUC8 and COPD, and that the specific short minisatellite alleles (2/2) of MUC8-MS5 may be a risk factor for COPD.     

Polymorphic markers <Emphasis Type="Italic">Val762Ala</Emphasis> and <Emphasis Type="Italic">Leu54Phe</Emphasis> of the <Emphasis Type="Italic">ADPRT1</Emphasis> gene associated with chronic glomerulonephritis in Russian patients from Moscow

A comparative analysis of allele and genotype distribution of polymorphic markers Val762Ala and Leu54Phe of ADPRT1 gene encoding poly(ADP-ribose)polymerase1 has been performed in chronic glomerulonephritis patients compared to normal controls. This has shown a significant difference in the ADPRT1 gene polymorphic marker Val762Ala allele and genotype frequency distribution between chronic glomerulonephritis patients and healthy controls (according to Fisher’s exact test). At the same time the allele and genotype frequency for a polymorphic marker Leu54Phe distribution did not show significant difference between these groups. Therefore, we have concluded that the ADPRT1 gene polymorphic marker Val762Ala is associated with the development of chronic glomerulonephritis in Russian patients of the Moscow region.     

Differential frequency of NKG2C/<Emphasis Type="Italic">KLRC2</Emphasis> deletion in distinct African populations and susceptibility to Trachoma: a new method for imputation of <Emphasis Type="Italic">KLRC2</Emphasis> genotypes from SNP genotyping data

NKG2C is an activating receptor that is preferentially expressed on natural killer (NK) cells. The gene encoding NKG2C (killer cell lectin-like receptor C2, KLRC2) is present at different copy numbers in the genomes of different individuals. Deletion at the NKG2C locus was investigated in a case–control study of 1522 individuals indigenous to East- and West-Africa and the association with the ocular Chlamydia trachomatis infection and its sequelae was explored. The frequency of homozygous KLRC2 deletion was 13.7 % in Gambians and 4.7 % in Tanzanians. A significantly higher frequency of the deletion allele was found in West-Africans from the Gambia and Guinea-Bissau (36.2 % p = 2.105 × 10^?8, 26.8 % p = 0.050; respectively) in comparison to East-African Tanzanians where the frequency of the deletion is comparable to other human populations (20.9 %). We found no evidence for an association between the numbers of KLRC2 gene copies and the clinical manifestations of trachoma (follicular trachoma or conjunctival scarring). A new method for imputation of KLRC2 genotypes from single nucleotide polymorphism (SNP) data in 2621 individuals from the Gambia further confirmed these results. Our data suggest that NKG2C does not play a major role in trachomatous disease. We found that the deletion allele is present at different frequencies in different populations but the reason behind these differences is currently not understood. The new method offers the potential to use SNP arrays from genome wide association studies to study the frequency of KLRC2 deletion in other populations and its association with other diseases.     

Comparison <Emphasis Type="Italic">CCR5del32</Emphasis> Mutation in the <Emphasis Type="Italic">CCR5</Emphasis> Gene Frequencies in Russians,Tuvinians, and in Groups of HIV-Infected Individuals

The 32-bp deletion (CCR5del32 mutation) in the CCR5 (chemokine (C-C motif) receptor 5) gene, encoding CCR5 chemokine receptor, is one of the factors determining natural resistance to human immunodeficiency virus (HIV-1) infection. In the present study, the samples of Russians (n = 102), Tuvinians (n = 50), and HIV-infected individuals (n = 107) were examined for the presence of CCR5del32 mutation in the CCR5 gene. The CCR5del32 allele frequency in Russians and Tuvinians constituted 7.84 and 2%, respectively. Among HIV-1 infected individuals, two groups, of macrophage-tropic HIV-1 strain- and T-cell-tropic HIV-1 strain-infected were distinguished. The CCR5del32 allele frequency in the first group (6.45%) was lower than in the second one (8.73%). Statistical treatment of the HIV-1 infected individuals typing data showed that the difference in the CCR5del32 allele frequencies between the groups of sexually (macrophage-tropic) and parenterally (T-cell-tropic) infected individuals observed was within the limit of random deviation.     

H558R,a common SCN5A polymorphism,modifies the clinical phenotype of Brugada syndrome by modulating DNA methylation of <Emphasis Type="Italic">SCN5A</Emphasis> promoters

Background

A common SCN5A polymorphism H558R (c.1673 A?>?G, rs1805124) improves sodium channel activity in mutated channels and known to be a genetic modifier of Brugada syndrome patients (BrS). We investigated clinical manifestations and underlying mechanisms of H558R in BrS.

Methods and results

We genotyped H558R in 100 BrS (mean age 45?±?14 years; 91 men) and 1875 controls (mean age 54?±?18 years; 1546 men). We compared clinical parameters in BrS with and without H558R (H558R+ vs. H558R- group, N?=?9 vs. 91). We also obtained right atrial sections from 30 patients during aortic aneurysm operations and compared SCN5A expression and methylation with or without H558R. H558R was less frequent in BrS than controls (9.0% vs. 19.2%, P?=?0.028). The VF occurrence ratio was significantly lower (0% vs. 29.7%, P?=?0.03) and spontaneous type 1 ECG was less observed in H558R+ than H558R- group (33.3% vs. 74.7%, P?=?0.01). The SCN5A expression level was significantly higher and the methylation rate was significantly lower in sections with H558R (N?=?10) than those without (0.98?±?0.14 vs. 0.83?±?0.19, P?=?0.04; 0.7?±?0.2% vs. 1.6?±?0.1%, P?=?0.004, respectively). In BrS with heterozygous H558R, the A allele mRNA expression was 1.38 fold higher than G allele expression.

Conclusion

The SCN5A polymorphism H558R may be a modifier that protects against VF occurrence in BrS. The H558R decreased the SCN5A promoter methylation and increased the expression level in cardiac tissue. An allelic expression imbalance in BrS with a heterozygous H558R may also contribute to the protective effects in heterozygous mutations.

     

Prevalence of common <Emphasis Type="Italic">MEFV</Emphasis> mutations and carrier frequencies in a large cohort of Iranian populations

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disorder caused by mutations in the MEFV gene. The disease is especially common among Armenian, Turkish, Jewish and Middle East Arab populations. To identify the frequency and the spectrum of common MEFV mutations in different Iranian populations, we investigated a cohort of 208 unselected asymptomatic individuals and 743 FMF patients. Nine hundred and fifty-one samples were analysed for the presence of 12 MEFV mutations by PCR and reverse-hybridization (FMF StripAssay, ViennaLab, Vienna, Austria). Confirmatory dideoxy sequencing of all MEFV gene exons was performed for 39 patients. Fifty-seven (27.4%) healthy individual carried mutant MEFV alleles. Three hundred and ninety-one (52.6%) FMF patients were found positive for either one (172/743; 23.1%), two or three MEFV mutations. Using dideoxy sequencing, three novel variants, A66P, R202W and H300Q, could be identified. Our analysis revealed an allele frequency and carrier rate of 15.6 and 27.4%, respectively, among healthy Iranians. Still moderate compared to neighbouring Armenia, but higher than in Turkey or Iraq, these data suggest that FMF is remarkably common among Iranian populations. E148Q was most frequent in the group of healthy individuals, whereas M694V was the most common mutation among FMF patients, thereby corroborating previous studies on MEFV mutational spectra in the Middle East. Accordingly, MEFV mutations are frequent in healthy Iranian individuals across different ethnic groups. Based on this finding, the awareness for FMF and the implementation of augmented carrier screening programmes considering the multiethnic nature of the Iranian population should be promoted.     

Association of <Emphasis Type="Italic">XPA</Emphasis> Polymorphisms Towards Lung Cancer Susceptibility and its Predictive Role in Overall Survival of North Indians

The present study investigated the role of Xeroderma pigmentosum group A (XPA) polymorphism (A23G and G709A) with lung cancer risk and its association with overall survival in North Indians. 370 cases and 370 controls were investigated to evaluate association between XPA polymorphism (A23G and G709A) with lung cancer risk using logistic regression analysis. A follow-up study was also conducted for 291 lung cancer cases illustrating correlation between overall survival in lung cancer patients and XPA variants. GG genotype showed an increased lung cancer risk (p = 0.0007) for A23G polymorphism whereas G709A polymorphism was associated with significant protective effect in heterozygous (AG) subjects (p = 0.001). When stratified according to smoking status an increased risk for lung cancer was observed for GG genotype in A23G polymorphism (p = 0.0002). A poor survival in females carrying variant genotype (GG) was observed (p = 0.001; MST = 4.16 months) for A23G polymorphism. Adenocarcinoma patients with heterozygous genotype showed an increased hazard ratio (p = 0.02) for A23G polymorphism. G709A was associated with a reduced hazard ratio marking a better survival among mutant females (HR 0.17; p = 0.05; MST = 18.63 months). It can be concluded that A23G polymorphism might contribute to increased lung cancer risk in North Indian population emphasizing on poor survival among females. G709A polymorphism might result in protective effect in lung cancer subjects. The present study had a low sample size but it could act as reference for the large sample studies in future.     

Association of <Emphasis Type="Italic">FGFR2</Emphasis> (rs2981579) gene polymorphism with the risk of mesial occlusion

The molecular-genetic testing of the polymorphic rs2981579 (C>T) locus of the FGFR2 gene as the marker of increased predisposition to the development of mesial occlusion was carried out in 110 patients with mesial occlusion and 103 general-population control subjects from Ukraine. It was shown that polymorphism rs2981579 in gene FGFR2 is associated with mesial occlusion (OR = 1.67, 95% CI = 1.14–2.45, p = 0.009). Compared to CC carriers, TT+CT carriers had a 3.21-fold higher risk of mesial occlusion (95% CI = 1.57–6.57, p = 0.001). We found the protective effect of the homozygous allele C on mesial occlusion development (OR = 0.31, p = 0.001). This is the first published data on FGFR2 polymorphisms rs2981579 (C>T) in patients with mesial occlusion.     

Genetic polymorphisms of <Emphasis Type="Italic">T-1131C APOA5</Emphasis> and <Emphasis Type="Italic">ALOX5AP SG13S114</Emphasis> with the susceptibility of ischaemic stroke in Morocco

Ischaemic stroke is a multifactorial disease. Genetic polymorphisms involved in lipid, inflammatory and thrombotic metabolisms play an important role in the development of ischaemic stroke. The present study aimed to assess the relationship between T1131C APOA5 and SG13S114 ALOX5AP polymorphisms and the risk of ischemic stroke in 175 cases and 201 controls. Genotyping was performed by high resolution melting and polymerase chain reaction restriction fragment length polymorphism methods. In the case of T-1131C APOA5, a modest risk of ischaemic stroke was noticed with CC (OR: 2.86; 95% CI = 1.24–6.58; Pc = 0.039) and C allele (OR: 1.54; 95% CI = 1.01–2.33; Pc = 0.014). For SG13S114ALOX5AP, a significant association was observed among subjects with TT (OR: 2.57; 95% CI =1.49–4.83; Pc = 0.009) and T allele (OR: 1.59; 95% CI = 1.16–2.19; Pc = 0.008). According to the risk factors of ischaemic stroke, a positive correlation was observed only between SG13S114 variant of ALOX5AP gene and hypertension (Pc = 0.026). Despite lower sample size, T-1131C APOA5 and SG13S114 variants could be considered an independent genetic risk factor of ischaemic stroke in Moroccan population.     

Search for associations between <Emphasis Type="Italic">G/A</Emphasis> polymorphism of the <Emphasis Type="Italic">EPAS1</Emphasis> gene and the maximal oxygen consumption in Russian athletes

This study investigates associations between G/A polymorphism of the epithelial PAS domain protein 1 (EPAS1) gene (rs1867785) and the maximum rate of oxygen consumption (VO_2max) in male Russian athletes. The study engaged 241 male athletes from different sports; the control group of nonathletes included 92 subjects. Increased frequencies of the AA and AG genotypes of the EPAS1 gene (χ² = 14.16, p = 0.03) were found in the cohort of male athletes. The frequencies of these alleles in the subgroups with moderate (EPAS1*A 38.1% and EPAS1*G 61.9%) and high (EPAS1*A 41.8% and EPAS1*G 58.2%) VO_2max values significantly differed from those in the control group (χ² = 7.53, p = 0.006 and χ² = 6.58, p = 0.01, respectively). The higher aerobic capacities are probably associated with the presence of at least one minor A allele of the EPAS1 gene in the genome.     

The <Emphasis Type="Italic">GPX1</Emphasis> Pro<Superscript>198</Superscript>Leu polymorphism in gastric cancer patients with and without <Emphasis Type="Italic">Helicobacter pylori</Emphasis> infection

Helicobacter pylori infection could induce oxidative stress. Oxidative stress is involved in the pathogenesis of gastric diseases. Glutathione peroxidase 1 (GPX1), is part of the enzymatic antioxidant defense, preventing oxidative damage. The aim of the present study was to assess the association of GPX1 Pro¹⁹⁸Leu genotypes with gastric cancer in patients with and without H. pylori infection in a population of Northern Iran. The present case-control study consisted of 50 patients with gastric cancer and 78 cancer-free subjects as controls. Extraction of DNA was performed on bioptic samples and the GPX1 genotypes were identified using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The frequencies of GPX1 Pro/Pro, Pro/Leu and Leu/Leu genotypes in controls were 21.8, 71.8 and 6.4%, respectively. However, in gastric cancer patients, the frequencies of 34, 56 and 10% were observed for Pro/Pro, Pro/Leu and Leu/Leu genotypes, respectively (p?=?0.185). In 38 (76%) patients infected with H. pylori, the frequencies of Pro and Leu alleles were 94.7 and 3.3%, respectively. There was a higher frequency of combined genotype of Pro/Leu?+?Leu/Leu (94.7%) in H. pylori positive patients than that in patients without H. pylori infection (75%, p?=?0.047). The presence of this genotype tended to increase the risk of H. pylori related gastric cancer by 5.88–fold (p?=?0.069) in our population. Our findings indicated the absence of association between the GPX1 Pro¹⁹⁸Leu polymorphism and the risk of gastric cancer in an Iranian population. However, we detected an association between H. pylori related gastric cancer with GPX1 Pro/Leu?+?Leu/Leu genotype.     

Polymorphism of pigmentation genes (<Emphasis Type="Italic">OCA2</Emphasis> and <Emphasis Type="Italic">ASIP</Emphasis>) in some populations of Russia

In Russian populations, polymorphism of two pigmentation system genes, OCA2 (loci 305, 355, and 419, tested in Russians, Buryats, Chukchi, Koryaks, and Evens) and ASIP (locus 8818, tested in Russians and Buryats) was examined. Pairwise comparisons of the F _ST distances between the populations showed that only the populations from Northeast Asia (Chukchi, Koryaks, and Evens) were statistically significantly different from all other populations, at least relative to one of the OCA2 locus. In Russians from Pskov oblast and Novgorod oblast, increased frequency (up to 6%) of the OCA2 allele 419A was revealed. In earlier studies, as association of this allele with green eye color was demonstrated. The data obtained in terms of their application for ethnic population genetics.     

Associations of <Emphasis Type="Italic">CTLA4</Emphasis> +49 A/G Dimorphism and HLA-DRB1*/DQB1* Alleles With Type 1 Diabetes from South India

The aim of present study was to elucidate the association of CTLA4 +49 A/G and HLA-DRB1*/DQB1* gene polymorphism in south Indian T1DM patients. The patients and controls (n?=?196 each) were enrolled for CTLA4 and HLA-DRB1*/DQB1* genotyping by RFLP/PCR-SSP methods. The increased frequencies of CTLA4 ‘AG’ (OR?=?1.99; p?=?0.001), ‘GG’ (OR?=?3.94; p?=?0.001) genotypes, and ‘G’ allele (OR?=?2.42; p?=?9.26?×?10^?8) were observed in patients. Reduced frequencies of ‘AA’ (OR?=?0.35; p?=?7.19?×?10^?7) and ‘A’ (OR?=?0.41; p?=?9.26?×?10^?8) in patients revealed protective association. Among HLA-DRB1*/DQB1* alleles, DRB1*04 (OR?=?3.29; p?=?1.0?×?10^?5), DRB1*03 (OR?=?2.81; p?=?1.9?×?10^?6), DQB1*02:01 (OR?=?2.93; p?=?1.65?×?10^?5), DQB1*02:02 (OR?=?3.38; p?=?0.0003), and DQB1*03:02 (OR?=?7.72; p?=?0.0003) were in susceptible association. Decreased frequencies of alleles, DRB1*15 (OR?=?0.32; p?=?2.55?×?10^?7), DRB1*10 (OR?=?0.45; p?=?0.002), DQB1*06:01 (OR?=?0.43; p?=?0.0001), and DQB1*05:02 (OR?=?0.28; p?=?2.1?×?10^?4) in patients were suggested protective association. The combination of DRB1*03+AG (OR?=?5.21; p?=?1.4?×?10^?6), DRB1*04+AG (OR?=?2.14; p?=?0.053), DRB1*04+GG (OR?=?5.21; p?=?0.036), DQB1*02:01+AG (OR?=?4.44; p?=?3.6?×?10^?5), DQB1*02:02+AG (OR?=?20.9; p?=?9.5?×?10^?4), and DQB1*02:02+GG (OR?=?4.06; p?=?0.036) revealed susceptible association. However, the combination of DRB1*10+AA (OR?=?0.35; p?=?0.003), DRB1*15+AA (OR?=?0.22; p?=?5.3?×?10^?7), DQB1*05:01+AA (OR?=?0.45; p?=?0.007), DQB1*05:02+AA (OR?=?0.17; p?=?1.7?×?10^?4), DQB1*06:01+AA (OR?=?0.40; p?=?0.002), and DQB1*06:02+AG (OR?=?0.34; p?=?0.001) showed decreased frequency in patients, suggesting protective association. In conclusion, CTLA4/HLA-DR/DQ genotypic combinations revealed strong susceptible/protective association toward T1DM in south India. A female preponderance in disease associations was also documented.