The 19-bp deletion polymorphism of dihydrofolate reductase (DHFR) and nonsyndromic cleft lip with or without cleft palate: evidence for a protective role

Objective Nonsyndromic cleft lip with or without cleft palate (NS-CL/P) are among the most common congenital birth defects worldwide. Several lines of evidence point to the involvement of folate, as well as folate metabolizing enzymes in risk reduction of orofacial clefts. Dihydrofolate reductase (DHFR) enzyme participates in the metabolic cycle of folate and has a crucial role in DNA synthesis, a fundamental feature of gestation and development. A functional polymorphic 19-bp deletion within intron-1 of DHFR has been associated with the risk of common congenital malformations. The present study aimed to evaluate the possible association between DHFR 19-bp deletion polymorphism and susceptibility to NS-CL/P in an Iranian population. Material and Methods The current study recruited 100 NS-CL/P patients and 100 healthy controls. DHFR 19-bp deletion was determined using an allele specific-PCR method. Results We observed the DHFR 19-bp homozygous deletion genotype (D/D) vs. homozygous wild genotype (WW) was more frequent in controls than in NS-CL/P patients (25% vs. 13%), being associated with a reduced risk of NS-CL/P in both codominant (OR=0.33, P=0.027) and recessive (OR=0.45, P=0.046) tested inheritance models. We also stratified the cleft patients and reanalyzed the data. The association trend for CL+CL/P group compared to the controls revealed that the DD genotype in both codominant (OR=0.30, P=0.032) and recessive models (OR=0.35, P=0.031) was associated with a reduced risk of CL+CL/P. Conclusions Our results for the first time suggested the DHFR 19-bp D/D genotype may confer a reduced risk of NS-CL/P and might act as a protective factor against NS-CL/P in the Iranian subjects. .

Association between toll-like receptor2 Arg677Trp and 597T/C gene polymorphisms and pulmonary tuberculosis in Zahedan, Southeast Iran

BACKGROUND: It is well known that toll-like receptor 2 (TLR2) mediates responses of both innate and adaptive immunity to microbial pathogen, including mycobacteria. Single-nucleotide polymorphisms (SNPs) in the TLR2 gene that impair its function may be associated with the development of pulmonary tuberculosis (PTB). The aim of this study was to evaluate the possible association between TLR2 Arg677Trp and 597T/C polymorphisms and PTB in a sample of Iranian population. MATERIALS AND METHODS: This case-;control study was performed on 174 PTB and 177 healthy subjects. Tetra amplification refractory mutation system-polymerase chain reaction (TARMS-PCR) was used to detect the SNPs. RESULTS: There was no significant difference in the polymorphism of Arg677Trp of the TLR2 gene among PTB and control groups (p > 0.05). The results showed that there was a significant difference between case and control groups regarding 597T/C polymorphism (χ2 = 12.21, p = 0.002). The TC and CC genotypes were found to be associated with the risk of PTB (OR = 2.13, 95% CI = 1.25-;3.62, p = 0.005 and OR = 4.88, 95% CI = 1.56-;15.26, p = 0.007, respectively). CONCLUSION: Our data suggest that 597T/C polymorphism, but not Arg677Trp polymorphism, of the TLR-2 gene is a risk factor for susceptibility to PTB in a sample of Iranian population.

Associação entre o polimorfismo rs7700944 no gene TIM-4 e artrite reumatoide em Zahedan, sudeste do Irã / Association between the rs7700944 polymorphism in the TIM-4 gene and rheumatoid arthritis in Zahedan, southeast Iran

INTRODUÇÃO: Recentemente, relatou-se uma associação entre artrite reumatoide (AR) e a variante rs7700944 G>A nos domínios imunoglobulina e mucina de células T (TIM-4). OBJETIVO: Investigar o impacto desse polimorfismo na suscetibilidade a AR em uma amostra da população iraniana. PACIENTES E MÉTODOS: Este estudo caso-controle foi conduzido em 120 pacientes com AR e 120 indivíduos saudáveis. O polimorfismo rs7700944 do gene TIM-4 foi determinado usando-se o ensaio tetra amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). RESULTADOS: Não se observou diferença significativa quanto ao polimorfismo rs7700944 do gene TIM-4 entre os pacientes com AR e os indivíduos saudáveis. Nas mulheres, não houve associação significativa quanto ao polimorfismo rs7700944 do gene TIM-4 nos dois grupos. Nos homens, o genótipo GA+AA, em comparação ao GG, aumentou o risco para AR (OR = 5,15; IC 95% = 1,30-20,48; P = 0,020). Além disso, os resultados mostraram que o alelo rs7700944 A aumentou o risco para AR (OR = 4,39; IC 95% = 1,43-13,54; P = 0,009). CONCLUSÃO: Nossos resultados não confirmam a existência de associação entre AR e o polimorfismo rs7700944 do gene TIM-4. Uma interação entre esse polimorfismo e sexo sugere uma associação sexo-específica entre AR e esse polimorfismo de nucleotídeo único, que ainda requer elucidação.

INTRODUCTION: Recently, an association between rheumatoid arthritis (RA) and the rs7700944 G>A variant in the T-cell immunoglobulin and mucin domains 4 (TIM-4) has been reported. OBJECTIVE: The present study aimed at investigating the impact of that polymorphism on susceptibility to RA in a sample of the Iranian population. Patients and methods: This case-control study was conducted on 120 patients with RA and 120 healthy subjects. The rs7700944 polymorphism in the TIM-4 gene was determined using tetra amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) assay. RESULTS: No significant difference was observed regarding the rs7700944 polymorphism of the TIM-4 gene between patients with RA and normal individuals. In females, no significant association was found between the groups concerning the rs7700944 polymorphism of the TIM-4 gene. In males, the GA+AA genotype increased the risk of RA in comparison with the GG genotype (OR = 5.15, 95% CI = 1.30-20.48, P = 0.020). Furthermore the results showed that the rs7700944 A allele increased the risk of RA (OR = 4.39, 95% CI = 1.43-13.54, P = 0.009). CONCLUSION: Our results do not support an association between the rs7700944 polymorphism of the TIM-4 gene and RA. An interaction between this polymorphism and sex suggests a sex-specific association between this single nucleotide polymorphism and RA, which remains to be fully elucidated.