Association of vdr,cyp27b1, cyp24a1 and mthfr gene polymorphisms with oral lichen planus risk

Objectives

The current study investigated the association between VDR EcoRV (rs4516035), FokI (rs2228570), ApaI (rs7975232) and TaqI (rs731236), CYP27B1 (rs4646536), CYP24A1 (rs2296241), and MTHFR (rs1801133) gene polymorphisms and risk of oral lichen planus (OLP) occurrence.

Materials and methods

The study group consisted of 65 oral lichen planus patients and 100 healthy blood donors in the control group. Single nucleotide polymorphisms were genotyped by real time PCR or PCR-restriction fragment length polymorphism (RFLP) method.

Results

Heterozygous as well as mutated genotype of vitamin D receptor (VDR) FokI (rs2228570) polymorphism was associated with increased oral lichen planus risk in comparison with wild type genotype (odds ratio (OR) = 3.877, p = 0.017, OR = 38.153, p = 0.001, respectively). A significantly decreased OLP risk was observed for heterozygous genotype of rs2296241 polymorphism in CYP24A1 gene compared with the wild type form (OR = 0.314, p = 0.012). VDR gene polymorphisms ApaI and TaqI were in linkage disequilibrium (D’ = 0.71, r ² = 0.22). Identified haplotype AT was associated with decreased OLP risk (OR = 0.592, p = 0.047).

Conclusion

Our results highlight the possible important role of VDR FokI (rs2228570) and CYP24A1 rs2296241 gene polymorphisms for oral lichen planus susceptibility.

Clinical relevance

Identification of new molecular biomarkers could potentially contribute to determination of individuals with OLP predisposition.

     

Polymorphism of the CD14 and TLR4 Genes and Post-treatment Apical Periodontitis

Introduction

This study investigated the association of CD14 -260C>T and TLR4 +896A>G gene polymorphisms with post-treatment apical periodontitis in Brazilian individuals.

Methods

The study population consisted of 41 patients with post-treatment apical periodontitis and 42 individuals with root canal–treated teeth exhibiting healed/healing periradicular tissues (controls). All teeth had apical periodontitis lesions at the time of treatment, which was completed at least 1 year previously. Saliva was collected from the participants; DNA was extracted and used for CD14 and TLR4 genotyping using the polymerase chain reaction–restriction fragment length polymorphism approach and a real-time polymerase chain reaction TaqMan assay (Applied Biosystems, Foster City, CA), respectively.

Results

No specific genotype or allele of the CD14 and TLR4 genes or any combination thereof was positively associated with post-treatment apical periodontitis (P > .05).

Conclusions

Data from the present study suggest that polymorphisms in the CD14 and TLR4 genes do not influence the response to endodontic treatment of teeth with apical periodontitis.     

Tumour necrosis factor‐alpha gene polymorphisms and susceptibility to oral lichen planus

Oral Diseases (2011) 17 , 206–209 Objective: This study is aimed to investigate the association between OLP susceptibility and clinical type in the Thai population and three polymorphisms within the promoter region of the TNF‐α at positions ‐863, ‐308 and ‐238 which have putative functional significances. Materials and Methods: Genomic DNA from 75 Thai patients with OLP and 154 healthy controls were genotyped for TNF‐α polymorphisms – ‐863(rs1800630), ‐308(rs1800629), and ‐238(rs361525) – using polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP). Results: We found a higher proportion of TNF‐alpha‐308 AA genotype (high producer genotype) among OLP patients (5/75; 6.67%) when compared to healthy controls (1/154; 0.65%; OR = 10.93; 95% CI = 1.21–251.9). For other polymorphisms (‐863 and ‐238), we did not find any significant association with OLP development; this was also the case with haplotype analysis (‐863/‐308/‐238). Conclusion: TNF‐α‐308AA may play a relevant role in the susceptibility and severity of OLP in the Thai population. However, further investigation of this study is needed.     

Assessment of 14 functional gene polymorphisms in Japanese patients with oral lichen planus: a pilot case-control study

Oral lichen planus (OLP) is a refractory mucosal disease. Its pathogenesis is thought to involve immunologic and genetic alterations. To gain a better understanding of the genetic risk factors, the authors evaluated associations between 14 functional gene polymorphisms and OLP. 32 Japanese patients with OLP and 99 unrelated healthy Japanese controls were genotyped for 14 single nucleotide polymorphisms (SNPs) of genes that regulate host immune responses. Genotyping was performed with a modified version of the serial invasive signal amplification reaction. A trend towards over-representation of tumor necrosis factor receptor 2 (TNFR2) +587 G allele was found in the patients compared with the controls (allele frequency: P = 0.049). The other 13 SNPs were unassociated with OLP. These results suggest that TNFR2 +587 gene polymorphism may be associated with susceptibility to OLP.     

Polymorphisms of TLR4 but not CD14 are associated with a decreased risk of aggressive periodontitis

OBJECTIVE: To study whether there is an association between the frequency of functional polymorphisms in the toll-like receptor 4 (TLR4) and cluster differentiation 14 (CD14) genes and periodontitis. METHODOLOGY: Genotyping for the TLR4 single-nucleotide polymorphisms (SNPs) Asp299Gly, Thr399Ile and the CD14 SNPs -159 and -1359 was completed for subjects with periodontal disease compared with control subjects. Two disease populations were investigated: 73 subjects with aggressive periodontitis (AgP; 28 males, 45 females) and 95 males with chronic periodontitis (CP). The TLR4 and CD14 polymorphisms were determined using SNaPshot primer extension with capillary electrophoresis. Comparison of allele and genotype frequencies for each polymorphism was by Fisher's exact test or chi2 analysis. RESULTS: The TLR4 Asp299Gly genotype was present in a significantly (p=0.026) lower proportion of AgP subjects (5.5%) compared with control subjects (16.3%). The unadjusted odds ratio for the Asp299Gly genotype to be associated with AgP was 0.30, 95% confidence interval 0.10-0.91. No differences were found in the prevalence of the TLR4 Asp299Gly genotype in men with CP (18.9%) compared with an age-matched control group with no evidence of periodontitis (17%). In addition, there was no difference in the distribution of the CD14 polymorphisms in either the AgP or CP populations studied compared with controls. CONCLUSION: It is concluded that in West European Caucasians, the Asp299Gly TLR4 gene polymorphism is associated with a decreased risk of AgP but not CP. Promoter polymorphisms of the CD14 gene, however, did not influence susceptibility to inflammatory periodontitis in the population cohorts studied.     

Toll-like receptor 2 rs4696480 polymorphism and risk of oral cancer and oral potentially malignant disorder

ObjectivesThe aim of this study was to identify the possible association between TLR polymorphisms and an increased risk of developing head and neck cancer, including oral (OSCC) and laryngeal squamous cell carcinoma (LSCC), and oral potentially malignant disorders, such as oral lichenoid disease (OLD), including oral lichen planus (OLP) and oral lichenoid lesions (OLL).DesignThis case-control study included 40 OSCC, 35 LSCC, 175 OLD (129 OLP and 46 OLL) patients and 89 healthy controls, all of them from the Basque Country, Spain. Genetic polymorphisms in TLR1, TLR2, TLR4, TLR6, TLR9, and TLR10 were genotyped by TaqMan^® assays or pyrosequencing.ResultsThe chi-square analysis showed that the variant A of the SNP TLR2-rs4696480 polymorphism significantly increased the risk of OSCC (p = 0.03) and OLL (p = 0.02).ConclusionsThe TLR2-rs4696480 polymorphism may be relevant to OSCC and OLL susceptibility in this population encouraging further studies on the TLR2 pathway and its possible association with this group of oral potentially malignant disorders and oral cancer. This may also prove the use of TLR polymorphisms as risk markers for oral and laryngeal cancer.     

CIITA rs4774 and rs6498122 polymorphisms are associated with oral lichen planus in Chinese people: a case–control study

Oral lichen planus (OLP) is a common autoimmune inflammatory disorder that is difficult to cure, and its pathogenesis is still largely unknown. The major histocompatibility complex (MHC) class II transactivator (CIITA) gene has been reported to be an important candidate in some classical autoimmune diseases, and certain single nucleotide polymorphisms (SNPs) in CIITA have been confirmed to be associated with susceptibility to some autoimmune diseases. We conducted this research to investigate the existence of any correlation between OLP and SNPs in CIITA. A case–control study was performed to genotype 15 SNPs in the CIITA gene from 42 patients with OLP and from 86 controls; this was carried out by the PCR and then by a locus‐specific single‐base extension reaction. Allele detection was performed using matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry. The SNP rs4774 variant in exon 11 (+1614G/C, Gly500Ala) of CIITA is significantly associated with OLP in healthy persons, both in genotype frequency and in allele frequency. Another intronic SNP, rs6498122, showed significant differences only in allele frequency. In conclusion, our data show that the two SNPs rs4774 and rs6498122 are associated with OLP and could also indicate the autoimmune characteristics of OLP.     

TLR4 and TLR9 are induced in oral lichen planus

J Oral Pathol Med (2012) 41 : 741–747 Background: The role of Toll‐like receptors (TLRs) has been elucidated in many human infectious, autoimmune and neoplastic diseases. Previously, TLR2 and TLR4 expression in oral lichen planus (OLP) was described. The aim of our study was to examine expression patterns of TLR4 and TLR9 in normal oral mucosa and OLP and describe the effect of topical tacrolimus treatment on the expression of TLR4 and TLR9 in OLP. Methods: Toll‐like receptor 4 and TLR9 expression was analysed by immunohistochemistry in five samples of normal oral mucosa and 50 samples of OLP (31 representing clinically white and 19 clinically erythematous/erosive lesions). We evaluated also the effect of topical tacrolimus on TLR4 and TLR9 expression in a patient with OLP. Results: Toll‐like receptor 4 and TLR9 expression was increased in OLP epithelium compared with normal epithelium (P < 0.001); no significant difference between the two clinical types of OLP was observed. TLR9 expression was strongest in the superficial layer of the epithelium (P < 0.001), while the expression of TLR4 was strongest in the basal layer (P < 0.001). Treatment of OLP lesions with topical tacrolimus resulted in clinical improvement but had no effect on TLR expression levels. Conclusions: Toll‐like receptor 4 and TLR9 are induced in OLP; our finding confirms the results of a previous study. TLR4 and TLR9 may play a part in the pathogenesis of OLP. Further studies are needed to dissect the definitive role of TLRs in OLP pathogenesis and progression and to determine the effect of tacrolimus on the function of TLRs.     

DNA repair gene polymorphisms and risk of head and neck cancer in the Tunisian population

Altered activity of DNA repair enzymes may be involved in modulating cancer susceptibility and pathogenesis of head and neck cancer (HNC). We conducted a case–control study to test the association between three common single‐nucleotide polymorphisms of XRCC1, ERCC2, and ERCC3 genes with HNC risk in Tunisian patients. To the best of our knowle dge, this is the first report on polymorphisms in XRCC1, ERCC2, and ERCC3 and susceptibility to HNC in our population. The genotype analyses of XRCC1 Arg399Gln, ERCC2 Lys751Gln, and ERCC3 7122 A>G polymorphisms for 169 HNC patients, and 261 controls were performed using the PCR‐based restriction fragment length polymorphism. Stratification of the populations according to smoking and drinking habits and occupational exposure highlighted the importance of tobacco, alcohol, and toxic substance as three risk co‐factors for the development of HNC. Our study suggests that only the XRCC1 Arg399Gln polymorphism was associated with the risk of HNC in the Tunisian population (OR = 2.04; P = 0.001). Furthermore, the risk of HNC was associated with XRCC1 Arg399Gln polymorphism stratified by occupational exposure status (OR = 2.29; P = 0.024). However, no statistically significant association was observed between the risk of developing HNC and the ERCC2 Lys751Gln and ERCC3 A>G polymorphisms. These data suggest that the XRCC1 Arg399Gln polymorphism is associated with an increased risk of developing HNC, because it correlates with occupational exposure in Tunisian population.     

Mannose-binding lectin gene (MBL-2) polymorphism in oral lichen planus

TNF-α may be associated with the etiopathogenesis of oral lichen planus (OLP), and it has been suggested that polymorphism of mannose-binding lectin (MBL) increases the in vitro production of TNF- α. The aim of the present study was to assess the relevance of genetic diversity of MBL in OLP. The study sample comprised 90 individuals, 45 OLP patients and 45 healthy volunteers. MBL-2 gene was amplified using real-time PCR. Frequency of A/A genotype was 55.6% in OLP and 53.3% in healthy volunteers. Likewise, A/0 heterozygote genotype was found in 42.2% and 35.6%; 2.2% and 11.1%, had the recessive 0/0 genotype respectively. Frequencies of the “A” and “0” alleles were 77% and 23% in the OLP group and 71.2% in control group. There were no statistically significant differences regarding genotype frequency (p = 0.546) or allele frequency (p = 0.497). In conclusion, no significant association was found between polymorphism of MBL-2 gene and OLP.     

CD14 and TLR4 gene polymorphisms in adult periodontitis

Bacterial deposits, smoking, and host genetic factors play a major role in an individual's predisposition to periodontitis. Bacterial components are recognized by CD14 and toll-like receptor 4 (TLR4), resulting in a NF-kappaB-based inflammatory response. We hypothesized that functional CD14 and TLR4 polymorphisms contribute to periodontitis susceptibility. We aimed to investigate the occurrence of CD14-260C>T, TLR4 299Asp>Gly, and 399Thr>Ile gene polymorphisms in adult periodontititis. DNA was collected from 100 patients with severe periodontitis and from 99 periodontally healthy controls. The gene polymorphisms were determined by the PCR technique. The presence of the periodontal pathogens Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans, and whether the subjects smoked, was included in the analyses. The CD14-260T/T genotype was found in 34.0% of periodontitis patients and in 20.2% of controls. Logistic regression analysis adjusted for gender, age, smoking, and prevalence of P. gingivalis and A. actinomycetemcomitans showed an association between the CD14-260T/T genotype and periodontitis (P = 0.004, OR 3.0, 95% CI 1.4-6.9). We conclude that the CD14-260T/T genotype contributes to the susceptibility to severe periodontitis in Dutch Caucasians.     

Lack of association between IRF6 polymorphisms (rs2235371 and rs642961) and non‐syndromic cleft lip and/or palate in a Brazilian population

Oral Diseases (2010) 16 , 193–197 Background: Interferon regulatory factor 6 (IRF6) gene has emerged as a potential susceptibility gene for non‐syndromic cleft lip and/or palate (NSCL/P) in different populations. The aim of this study was to determine the association of IRF6 rs2235371 and rs642961 polymorphisms with NSCL/P in a Brazilian population. Methods: Two hundred and twenty‐eight patients affected by NSCL/P and 126 healthy individuals were genotyped by polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) assay. Results: Overall genotype distributions of rs2235371 and rs642961 polymorphisms were as expected by Hardy‐Weinberg equilibrium test. The rs2235371 polymorphic genotype GA was identified in 10.1% of the patients with NSCL/P and in 10.3% of the control group, revealing no statistical difference. Similarly, the frequency of rs642961 minor genotypes (GA and AA) was quite similar between control group (28.6%) and NSCL/P group (25.4%), without significant difference. Conclusion: Our findings are consistent with a lack of involvement of IRF6 rs2235371 and rs642961 polymorphisms in the NSCL/P pathogenesis in the Brazilian population.     

Association among Oral Health,Apical Periodontitis,CD14 Polymorphisms,and Coronary Heart Disease in Middle-aged Adults

Introduction

There is evidence to suggest that an association exists between oral infections and coronary heart disease (CHD). Subjects presenting lesions of endodontic origin (LEOs) or pulpal inflammation had an increased risk of developing CHD. However, findings concerning systemic manifestations of apical periodontitis (AP) remain controversial. An association between CD14 gene polymorphisms and atherosclerosis-associated diseases has been shown, but there are no data regarding an association between CD14 polymorphism and AP. This study evaluated associations between clinical oral health status, CD14 polymorphisms, and CHD.

Methods

A case-controlled clinical trial was designed to compare middle-aged adults with acute myocardial infarction or unstable angina (n = 51) within 12 months of the acute event defined as first manifestation with healthy controls (n = 49). Participants were matched for age, sex, and socioeconomic status. Indicators of oral disease and compliance were evaluated. CD14 polymorphisms were analyzed by restriction fragment length polymorphism–polymerase chain reaction.

Results

CHD subjects had a higher prevalence of oral diseases and lower compliance to oral preventive strategies than healthy controls. Multivariate analysis showed a positive association between missing teeth (odds ratio [OR] = 1.37; 95% confidence interval [CI], 1.02–1.85), the number of LEOs (OR = 4.37; 95% CI, 1.69–11.28), chronic periodontitis (OR = 5.87; 95% CI, 1.17–29.4), and CHD. No statistically significant association emerged between the CD14 C(−260)T and the CD14 C(−159)T polymorphism, endodontic or periodontal disease, and CHD.

Conclusions

Chronic oral diseases may increase the risk of CHD and may be an unconventional risk factor for CHD.     

Influence of methylenetetrahydrofolate reductase polymorphisms in oral cancer patients

J Oral Pathol Med (2011) 40 : 61–66 Background: Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism. Two common polymorphisms associated with MTHFR gene – C677T and A1298C – influence the thermolabile nature and activity of the enzyme. This study aimed to investigate the role of MTHFR polymorphisms on oral cancer susceptibility and its potential impact on the prognostic outcome. Methods: Oral cancer cases and controls were genotyped using PCR‐RFLP technique for MTHFR C677T and A1298C polymorphisms. Disease susceptibility analysed using regression analysis. The association between clinical outcomes and the polymorphisms were analysed using univariate and multivariate model. Results: The 677CT+TT genotype showed a significant three‐fold reduction in oral cancer risk (RR‐0.35, p‐0.009). 1298CC genotype showed decreased cancer risk when compared to AA+AC genotype (RR‐0.55, p‐0.062). When prognostic significance of MTHFR polymorphism was evaluated, 677CT+TT patients showed improved survival than the CC individuals (RR = 0.56, P = 0.378). The 1298 CC and AC+CC showed an increased risk for treatment failure and poor survival when compared with the wild AA genotype (HR = 4.27, P = 0.001). Conclusion: Here we observed MTHFR C677T to influence oral cancer susceptibility, while A1298C polymorphism associated with patient prognosis. Our data support MTHFR polymorphism to be an independent prognostic marker in oral carcinoma.     

5,10‐Methylenetetrahydrofolate reductase single nucleotide polymorphisms and gene–environment interaction analysis in non‐syndromic cleft lip/palate

Non‐syndromic cleft lip/palate (NSCL/P) is a common congenital defect in Mexico. Periconceptional intake of folic acid (FA) may reduce the risk of this malformation. Although the 5,10‐methylenetetrahydrofolate reductase (MTHFR) enzyme participates in folate metabolism, several studies failed to find any association between NSCL/P and the MTHFR C677T and A1298C polymorphisms. However, interactions among NSCL/P, MTHFR gene polymorphisms, and FA intake have not been explored in Mexican populations. This case–control study included 132 patients with NSCL/P and 370 controls from Mexico City. Maternal FA consumption during pregnancy was examined, as were the MTHFR C677T and A1298C polymorphisms and gene–FA interactions. Maternal FA intake during the periconceptional period was lower in cases (1.5%) than in controls (13%), with the risk of delivering a child with NSCL/P lower in mothers who consumed FA (OR = 0.29, 95% CI: 0.19–0.44). In addition, the risk of NSCL/P was lower in children with the TT than the CC genotype of MTHFR C677T (OR = 0.39, 95% CI: 0.23–0.68), after Bonferroni correction and exclusion of stratification. No evidence of gene–FA interaction was found. These results indicate that maternal FA intake and the TT genotype of the MTHFR C677T polymorphism in children independently reduced the risk of NSCL/P in our population.     

DEFB1 polymorphisms and salivary hBD-1 concentration in Oral Lichen Planus patients and healthy subjects

ObjectivesThe aetiology of Oral Lichen Planus (OLP), a chronic inflammatory disease of oral mucosa, is not yet well understood. Since innate immunity may be hypothesized as involved in the susceptibility to OLP, we studied human beta defensin 1 (hBD-1) an antimicrobial peptide constitutively expressed in the saliva, looking at functional genetic variants possibly able to diminish hBD-1 production an consequently conferring major susceptibility to OLP.DesignWe analysed three DEFB1 polymorphisms at 5′ UTR, −52G > A (rs1799946), −44C > G (rs1800972), −20G > A (rs11362) and two DEFB1 polymorphisms at 3′UTR, c*5G > A (rs1047031), c*87A > G (rs1800971), with the aim of correlating these genetic variants and hBD-1 salivary level in a group of OLP patients and in healthy subjects. We also evaluated hBD-1 salivary concentrations, using ELISA, in OLP and healthy controls.ResultsWe compared hBD-1 concentrations in OLP and healthy subjects: hBD-1 concentration was significantly higher in OLP patients respect to control.When considering the correlation between DEFB1 polymorphisms genotypes and hBD-1 expression levels, significant results were obtained for SNPs −52G > A (p = 0.03 both in OLP patients and healthy individuals) and −44C > G (p = 0.02 in OLP patients).ConclusionshBD-1 production was different between OLP and healthy subjects (not age-matched with OLP). DEFB1 gene polymorphisms, −52G > A and −44C > G, correlated with hBD-1 salivary concentrations.     

Single nucleotide polymorphisms of pattern recognition receptors and chronic periodontitis

Sahingur SE, Xia X‐J, Gunsolley J, Schenkein HA, Genco RJ, De Nardin E. Single nucleotide polymorphisms of pattern recognition receptors and chronic periodontitis. J Periodont Res 2011; 46: 184–192. © 2010 John Wiley & Sons A/S Background and Objective: Periodontitis is a multifactorial disease influenced partly by genetics. Activation of pattern recognition receptors (PRRs) can lead to the up‐regulation of inflammatory pathways, resulting in periodontal tissue destruction. Hence, functional polymorphisms located in PRRs can explain differences in host susceptibility to periodontitis. This study investigated single nucleotide polymorphisms of PRRs including toll‐like receptor (TLR)2 (G2408A), TLR4 (A896G), TLR9 (T1486C), TLR9 (T1237C) and CD14 (C260T) in patients with chronic periodontitis and in periodontally healthy subjects. Methods: One‐hundred and fourteen patients with chronic periodontitis and 77 periodontally healthy subjects were genotyped using TaqMan® allelic discrimination assays. Fisher’s exact test and chi‐square analyses were performed to compare genotype and allele frequencies. Results: The frequency of subjects with the CC genotype of CD14 (C260T) (24.6% in the chronic periodontitis group vs. 13% in the periodontally healthy group) and those expressing the T allele of CD14 (C260T) (CT and TT) (75.4% in the chronic periodontitis group vs. 87% in the periodontally healthy group) was statistically different among groups (p = 0.04). Homozygocity for the C allele of the CD14 (C260T) polymorphism (CC) was associated with a two‐‐fold increased susceptibility to periodontitis (p = 0.04; odds ratio, 2.49; 95% confidence interval, 1.06–6.26). Individuals with the CC genotype of TLR9 (T1486C) (14.9% in the chronic periodontitis group vs. 28.6% in the periodontally healthy group) and those expressing the T allele of TLR9 (T1486C) (CT and TT) (85.1% in the chronic periodontitis group vs. 71.4% in the periodontally healthy group) were also significantly differently distributed between groups without adjustment (p = 0.03). Further analysis of nonsmokers revealed a significant difference in the distribution of genotypes between groups for TLR9 (T1486C; p = 0.017) and CD14 (C260T; p = 0.03), polymorphisms again without adjustment. Conclusion: The CC genotype of CD14 (C260T) is related to susceptibility to chronic periodontitis in Caucasians. In addition, differences observed in the distribution of TLR9 (T1486C) genotypes between groups warrant further investigation.     

Genetic susceptibility to periodontitis

In this systematic review, we explore and summarize the peer‐reviewed literature on putative genetic risk factors for susceptibility to aggressive and chronic periodontitis. A comprehensive literature search on the PubMed database was performed using the keywords ‘periodontitis’ or ‘periodontal disease’ in combination with the words ‘genes’, ‘mutation’, ‘SNP’ or ‘polymorphism’. The studies selected were written in English, had a case–control design, and reported genotype distribution. Only studies with at least 100 individuals in either the case or control group were included. Research on genetic polymorphisms has only had limited success in identifying significant and reproducible genetic factors for susceptibility to aggressive periodontitis and chronic periodontitis. Taking together the data published on gene polymorphisms in aggressive and chronic periodontitis, we conclude that there are differences among the various studies for the rare allele carriage rates. Nevertheless, there is some evidence that polymorphisms in the IL1B, IL1RN, FcγRIIIb, VDR and TLR4 genes may be associated with aggressive periodontitis susceptibility, and polymorphisms in the IL1B, IL1RN, IL6, IL10, VDR, CD14, TLR4 and MMP1 genes may be associated with chronic periodontitis susceptibility as a single genetic factor in certain populations. Future studies should apply stricter disease classifications, use larger study cohorts, adjust for relevant risk factors in aggressive and chronic periodontiti,s and include analysis of multiple genes and polymorphisms. Establishing consortia and performing collaborative studies may help to conquer the limitations of small sample size and limited statistical power.     

Association of vitamin D receptor gene polymorphisms with chronic and aggressive periodontitis in Jordanian patients

Vitamin D acts through binding with vitamin D receptor (VDR) and is responsible for regulating bone metabolism and mineralization; it also suppresses the immune system. The aim of this study was to investigate if VDR gene polymorphisms are associated with chronic periodontitis (CP) and aggressive periodontitis (AgP) in a Jordanian population. A total of 99 patients with CP, 63 patients with AgP, and 126 controls were genotyped using PCR‐restriction fragment length polymorphism (RFLP) for BsmI, ApaI, and TaqI single nucleotide polymorphisms (SNPs). The association was determined after correcting for confounding factors using multivariate logistic regression analysis. Estimation of haplotype frequencies was carried out using the EH program, and haplotypes were constructed using the phase 2.1 program. After correcting for confounding factors, multivariate logistic regression analysis revealed that inheritance of the BsmI bb genotype or the ApaI aa genotype was associated with increased risk of developing CP (OR = 2.4 and OR = 3.4, respectively) but with reduced risk of developing AgP (OR = 0.4 and OR = 0.3, respectively). This was further supported by association of the ba haplotype with CP but not with AgP. This study supports an association of VDR gene polymorphisms with CP and AgP in a Jordanian population; however, the pattern of association was different between the two diseases.     

Genetic polymorphism of tumor necrosis factor alpha (TNF-α) and tumor necrosis factor beta (TNF-β) genes and risk of oral pre-cancer and cancer in North Indian population

Objective

There are inconclusive data connecting single-nucleotide polymorphisms (SNPs) of TNF-α (rs361525) and TNF-β (rs909253) to potential malignant oral disorder (PMOD) such as lichen planus and oral fibrosis. Here, we have investigated the risk of oral squamous cell carcinoma as well as oral pre-cancerous lesions in North Indian population with the polymorphism of the TNFα/ β genes.

Material and methods

A total 500 patients with oral pre-cancer and OSCC and 500 healthy volunteers were genotypes for the TNF-α (-238) G/A (rs361525) and TNF-β (252) A/G (rs909253) gene polymorphism. Genotypes were identified by polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP). Genotype frequencies were evaluated by Chi-square test.

Results

Compared to the GG genotype, the GA genotype of TNF-α (G238A) polymorphism (rs361525) has been found to significantly increase the risk of oral disease (OR = 1.99) and especially the risk of lichen planus and OSCC (OR = 2.805 and 5.790, respectively). Similarly, the risk of oral disease was also more in the heterozygote (AG) than the common allele homozygote (AA) of TNF-β (A252G) polymorphism (rs909253) (OR = 1.483).

Conclusion

We conclude that the SNPs rs361525 and rs909253 were significantly associated with oral pre-cancer and OSCC.