rs1801131

This study examined genetic and epigenetic markers associated with chemotherapy-induced oral mucositis in 87 pediatric patients with hematological neoplasms, with 81.9% developing mucositis. Global DNA methylation was significantly reduced in children who recovered from mucositis (18% vs 40% in healthy controls, p<0.05), and the DNMT1 rs2228611 SNP showed association with global methylation levels in cancer patients with mucositis history. miR-9-1 and miR-9-3 methylation patterns were associated with tumor status rather than mucositis.

This is a Turkish-language personalized nutrigenetics and epigenetics coaching report for individual Mehmet Efe Yildirim (Report No. 1332, dated 2023-11-21). The report analyzes the individual's genetic polymorphisms related to nutritional metabolism, food sensitivities, detoxification pathways, and other health-related traits, providing personalized dietary and lifestyle recommendations based on cited scientific literature. This is a direct-to-consumer genetic test report, not a peer-reviewed research study.

A prospective study of 91 primary central nervous system lymphoma (PCNSL) patients examined genetic polymorphisms in DNA repair, one-carbon metabolism, and metabolism genes as prognostic markers. ABCB1 rs1045642 was identified as an independent prognostic factor, with the CC genotype significantly associated with shorter progression-free survival (PFS: 16 months CC vs. 27 months TT/CT, HR=1.9, P=0.036) and higher risk of disease progression compared to T allele carriers.

A case-control study of 152 NTD patients and 169 controls in Han Chinese population identified three folate metabolism pathway SNPs associated with neural tube defects: rs2236225 in MTHFD1 (allele A, OR=1.500; AA genotype OR=2.862), rs1801133 in MTHFR (allele T, OR=1.552; TT genotype OR=2.344), and rs1801394 in MTRR (allele G, OR=1.533; GG genotype OR=2.355). The study demonstrates genetic variation in folate metabolism significantly affects NTD susceptibility.

A case-control study of 576 fetuses/newborns with neural tube defects (NTDs) and 594 controls in a Chinese population examined MTHFR and COMT gene variants. The MTHFR rs1801133 TT genotype was associated with increased NTD risk (OR=1.37), and a synergistic interaction between COMT rs737865 CC and MTHFR rs1801133 TT genotypes showed over 3-fold increased risk for NTDs (OR=3.02) and anencephaly (OR=3.39), suggesting these variants interact to modulate folate metabolism and increase birth defect susceptibility.

Case-control study of 501 young stroke patients and 1,211 controls examining 58 polymorphisms in 17 genes involved in methionine metabolism. Multiple logistic regression identified four independent risk factors for early-onset ischaemic stroke: rs10037045 BHMT (OR 1.38, p=0.033), rs682985 BHMT2 (OR 1.46, p=0.017), rs1051319 CBS (OR 3.75, p<0.0001), and rs202680 FOLH1 (OR 3.00, p<0.0001). Haplotype analyses identified significant associations with BHMT, CBS, FOLH1, MTR, PON2, TCN2 and TYMS haplotypes and stroke risk.

A hospital-based case-control study in rural and urban India (1,204 cases; 1,212 controls) examined genetic and lifestyle risk factors for breast cancer. Four SNPs in FGFR2 (rs1219648, rs2420946, rs2981575, rs2981582) showed positive associations with breast cancer (ORs 1.32-1.47). Additional SNPs in obesity and metabolic genes (rs374748 in FBN2, rs2922763 in HNF4G, rs2116830 in KCNMA1, rs11121832 in MTHFR, rs16886165 in MAP3K1, rs11594610 in TCF7L2, rs2274459 in MLN) were associated with increased breast cancer risk. Waist-to-hip ratio ≥0.95 showed strong association (OR 3.78; 95% CI 2.92-4.89), and women living first 20 years in rural areas showed protective effect (OR 0.77).

Population distribution study of MTHFR C677T (rs1801133) and A1298C (rs1801131) variants in Israeli subpopulations. Ashkenazi Jews showed 1.87-fold higher frequency of 677T allele and 1.81-fold lower frequency of 1298C allele compared to non-Ashkenazi Jews. These polymorphisms are associated with reduced MTHFR enzyme activity and methotrexate toxicity risk, with implications for personalized medicine and drug dosing.

Two SNPs in VKORC1 (rs9934438 and rs9923231) were identified as genetic risk factors for systemic lupus erythematosus (SLE) in Asian populations. In discovery cohort (263 SLE cases, 357 controls), both SNPs showed strong associations (OR=2.40-2.45, p=6.1×10^-9 to 2.4×10^-9), which were confirmed in a larger replication cohort (1496 cases, 993 controls) with OR=1.53-1.54 (p=4.3-5.1×10^-6), and remained significant after ancestry adjustment (OR=1.34, p=0.0029-0.0032).

This meta-analysis of 106 studies (100 articles, 625 total retrieved) evaluates associations between MTHFR gene polymorphisms (C677T rs1801133 and A1298C rs1801131) and colorectal cancer (CRC) risk across 37 Asian, 50 Caucasian, 6 Indian, 4 African, and 7 mixed-race populations. MTHFR C677T polymorphism reduces CRC risk in Asian and mixed-race populations but increases risk in Indians. MTHFR A1298C polymorphism may play a protective role in CRC development, with several genetic models showing reduced susceptibility (e.g., CC vs AA: OR=0.729, 95% CI=0.582-0.913; C vs A: OR=0.905, 95% CI=0.833-0.984).

Meta-analysis of 83 case-control studies (35,758 individuals) examining associations between homocysteine levels, folate, vitamin B12, and MTHFR polymorphisms with cancer risk. High homocysteine levels showed strong association with overall cancer risk (OR 5.06, 95% CI 4.59-5.52), while low folate was protective (OR -2.68). MTHFR C677T TT/CC genotype showed significant association with cancer risk (OR 1.18, 95% CI 1.05-1.33).

This comprehensive review examines the genetic background of nonalcoholic fatty liver disease (NAFLD), focusing on variants identified by genome-wide association studies (GWAS) and candidate gene studies. The most significant GWAS-identified variants are PNPLA3 rs738409 (I148M), which strongly associates with increased liver steatosis, fibrosis severity, and HCC risk (12-fold increased risk for homozygous carriers), and TM6SF2 rs58542926 (E167K), which increases NASH progression but reduces cardiovascular risk. The review also discusses numerous candidate genes involved in lipid and glucose metabolism and liver injury mechanisms.

This is a comprehensive journal compilation containing multiple oncology and pharmacogenomics studies published in 2013 across various journals. The collection includes 60+ papers covering cancer treatment outcomes, genetic polymorphisms predicting chemotherapy response and survival, pharmacogenetic variants in drug metabolism and DNA repair genes, and prognostic biomarkers in various cancer types including breast, lung, colorectal, hematologic malignancies, and others. Key findings include associations of XRCC1 variants (rs915927, rs76507, rs2854501, rs2854509, rs3213255) with bladder cancer chemotherapy survival, ABCG2 rs2725264 with lung cancer overall survival (HR 3.22), SLCO1B1 rs4149056 with methotrexate pharmacokinetics, MTHFR rs1801131 with acute lymphoblastic leukemia outcome, and ABCC3/GSTM variants with acute myeloid leukemia survival.

This study examined PAH-related DNA adduct levels in 111 female never-smokers from Iran, evaluating 21 SNPs in 14 xenobiotic metabolism genes and 12 SNPs in 8 DNA repair genes. DNA adduct levels were significantly lower with NAT2 slow alleles (β=-0.24, p=0.01) and ERCC5 non-risk genotype (β=0.16, p=0.04), but higher with MPO risk alleles (β=0.21, p=0.01). The combination of phase I genes and measured NER capacity explained 17% more variation in adduct levels than environmental exposure alone (r²=0.24 vs 0.07), demonstrating the importance of genetic polymorphisms in PAH metabolism and DNA repair capacity.

This document is a comprehensive collection of ~1,200 cancer-related research abstracts and summaries published in various journals (2013), covering clinical trials, pharmacogenomic studies, and mutation analyses across multiple cancer types including colorectal, breast, lung, lymphoma, and other malignancies. The collection documents associations between genetic variants (SNPs and somatic mutations), gene expression patterns, and cancer treatment outcomes, including studies on KRAS, EGFR, TP53, BRAF, and pharmacogenomic variants like CYP3A4 and UGT1A1.

A retrospective candidate gene association study of 136 lung cancer patients found that the MTHFR 1298A>C polymorphism (rs1801131) was associated with reduced risk of grade ≥2 radiation pneumonitis after thoracic radiation therapy (adjusted hazard ratio 0.37, 95% CI: 0.18-0.76, p=0.006). The SOD2 polymorphism (rs4880) and another MTHFR variant (rs1801133) showed no significant association with radiation pneumonitis risk.

This case-control study of 135 lung cancer patients examined associations between MTHFR polymorphisms (C677T rs1801133 and A1298C rs1801131), dietary folate intake, and DNA adducts in lung tissue. The A1298C variant (AC+CC) was associated with a 69.2% increase in lung DNA adducts (95% CI: 5.5%-171.5%), while the combined high-risk genotype (C677T CT+TT plus A1298C AC+CC) showed a 210.7% increase (95% CI: 21.4%-695.2%, P=0.02) in adducts. Low folate intake significantly exacerbated DNA damage in carriers of the A1298C variant, with 111.3% increased adducts among those with lowest tertile folate consumption.

This case-control study examined 29 polymorphisms in four folate-mediated one-carbon metabolism pathway genes (MTHFD1, SHMT1, MTHFR, DHFR) in Hispanic and non-Hispanic white populations to assess their association with conotruncal heart defects. MTHFD1 rs11627387 was associated with a 1.7-fold increased risk in both Hispanic mothers (OR=1.7, 95% CI=1.1-2.5) and Hispanic infants (OR=1.7, 95% CI=1.2-2.3). MTHFR rs1801133 (C677T) showed a 2.8-fold increased risk among Hispanic mothers with low dietary folate intake, while rs1801131 (A1298C) showed a 2.0-fold increased risk among those with higher folate intake. Gene-folate interactions were observed, suggesting maternal multivitamin use and dietary folate intake may modify conotruncal heart defect risk.

This case-control association study examined genetic polymorphisms in 237 Russian women to identify variants associated with early reproductive loss and recurrent miscarriage. The study found that DNMT3B rs2424913 (OR=4.44-4.78), DNMT1 rs2228611 (OR=3.0-3.94), and DNMT1 rs8101626 (OR=2.5-3.1) were significantly associated with increased risk of sporadic and recurrent early pregnancy loss, while SYCP3 rs769825641 heterozygotes showed elevated risk of sporadic miscarriage.

This meta-analysis of five Nordic samples (2,198 schizophrenia patients) investigated the association between the MTHFR C677T polymorphism (rs1801133) and age at onset of schizophrenia. While an initial Scandinavian study reported that the T-allele was associated with earlier disease onset (1.8 years per allele, P=0.007 in Copenhagen), replication in two independent Danish and Icelandic samples failed to confirm this finding (P=0.10 in Aarhus, P=0.86 in Iceland). The pooled meta-analysis of all five studies found no significant association (P=0.17, β=0.42 years per T-allele), concluding that the initial finding was likely due to chance rather than a true genetic effect.

This deep sequencing study of the MTHFR gene identified variants associated with myelomeningocele (a neural tube defect) in 96 affected subjects (49 Caucasian, 47 Mexican American). The authors discovered one novel intronic splice site variant (c.171+3G>T) and found seven SNPs with significant allele frequency differences compared to ethnically matched reference populations (p ≤ 0.05, Fisher's exact test), including five SNPs (rs13306561, rs2274976, rs2066462, rs12121543, rs1476413) not previously associated with neural tube defects.

Case-control study (222 cases, 454 controls) examining gene-folate interactions in five folate-related genes (MTHFD1, MTHFR, SHMT1, DHFR, TYMS) and neural tube defect risk. Maternal MTHFR SNPs rs1476413, rs1801131, and rs1801133 showed decreased NTD risk with low folate intake (OR=0.55-0.69, 80% CI); infant MTHFD1 SNPs rs2236224, rs2236225, and rs11627387 showed increased risk (OR=1.53-4.25, 80% CI); maternal SHMT1 rs669340 showed protective gene-only effect (OR=0.69, 95% CI: 0.49-0.96).

Case-control study of 169 omphalocele cases and 761 controls examining variants in folate, vitamin B12, and homocysteine metabolism genes. Variants in transcobalamin receptor (TCblR) rs2232775 (Q8R) and methylenetetrahydrofolate reductase (MTHFR) rs1801131 (1298A>C) were significantly associated with omphalocele (TCblR OR=3.20, p=0.0017; MTHFR OR=2.04, p=0.028). Additional race-ethnicity-specific associations were found with TCN2, BHMT rs3733890, and FOLH1 variants, suggesting disruption of methylation reactions as a potential risk factor.

This case-control and family-based study evaluated 64 SNPs in 34 genes for associations with spina bifida in 558 Irish case-families and 994 controls. Spina bifida was significantly associated with LEPR rs1805134 (GRR: 1.5, P = 0.0264) and COMT rs737865 (GRR: 1.4, P = 0.0206), with additional confirmations of previous findings in MTHFR 677C>T and other genes, suggesting roles for leptin signaling and methylation pathways in neural tube defect pathogenesis.

This comprehensive review examines the genomics of schizophrenia and pharmacogenomics of antipsychotic drugs, synthesizing evidence on over 200 genes associated with psychotic disorders. The authors discuss five categories of genes relevant to antipsychotic response: disease-associated genes, mechanism-of-action genes, drug metabolism genes (particularly CYP2D6, CYP2C19, CYP2C9, CYP3A4), drug transporter genes, and pleiotropic genes. The review details pharmacogenomic profiles of 20+ antipsychotic drugs and demonstrates significant ethnic and interindividual variation in drug metabolism phenotypes, with examples including CYP2D6 extensive metabolizers (55.71% of population), intermediate metabolizers (34.7%), poor metabolizers (2.28%), and ultra-rapid metabolizers (7.31%).

This family-based association study examined 14 folate pathway genes using 89 SNPs in 445 NSCLP families (317 non-Hispanic White, 128 Hispanic) to identify genetic variants contributing to nonsyndromic cleft lip and palate. Evidence for association was found with SNPs in NOS3 and TYMS in the non-Hispanic White group (rs2373929/NOS3, rs502396/TYMS, and others), and with MTR, BHMT2, MTHFS, and SLC19A1 in the Hispanic group (rs1422086/BHMT2, rs2115540/MTHFS significant after Bonferroni correction). Multiple gene-gene interactions were detected, with CBS and MTHFD1 showing the most extensive interactions. Significant interactions were also found between several SNPs and maternal smoking and one SNP (rs651646/FOLR2) with offspring sex.

Comprehensive review of genetic background in nonalcoholic fatty liver disease (NAFLD). The PNPLA3 I148M variant (rs738409 C>G) is identified as a major genetic player strongly associated with increased liver fat content, NASH development, fibrosis severity, and HCC risk. The TM6SF2 E167K variant (rs58542926) emerges as another key contributor to NAFLD pathogenesis and disease progression. Multiple additional GWAS-identified variants and candidate genes are reviewed for their roles in NAFLD susceptibility and progression.

This case-control study examined folate pathway gene variants in 121 DS-AVSD cases and 122 DS controls (no CHD). Tag SNPs in MTHFR, MTR, MTRR, CBS, and SLC19A1 were genotyped. SLC19A1 showed significant gene-level association with atrioventricular septal defect (P=0.01), with multiple tag SNPs nominally associated (OR 1.08-1.72). All significant SLC19A1 SNPs showed strong LD (r²≥0.80) with the nonsynonymous variant rs1051266 (c.80A>G, p.H27R). MTHFR c.1298A was over-transmitted to cases (P=0.05) and under-transmitted to controls (P=0.02), showing association in FBAT analysis (P=0.03 dominant, P=0.01 additive). These results suggest folate pathway disruption contributes to AVSD risk in Down syndrome individuals.

A pathway-wide association study in 425 case-parent triads examined 109 SNPs in 29 folate/one-carbon metabolism genes and 68 SNPs in 16 vitamin A metabolism genes for associations with cleft lip/palate (CL/P) and cleft palate only (CPO). Despite strong epidemiologic evidence that folic acid and vitamin A reduce cleft risk, no convincing genetic associations were found; the strongest association was FOLH1 with CPO (p=0.0008), but findings were fewer than expected by chance and inconsistent with protective effects of vitamin supplementation, suggesting vitamin metabolism gene polymorphisms do not play an etiologic role in oral facial clefts.

This family-based association study examined 12 polymorphisms in one-carbon metabolism genes (BHMT, CBS, MTHFD1, MTHFR, MTR, MTRR, SLC19A1, TCN2) and their associations with oral facial clefts in 553 Norwegian families. CBS rs234706 showed a significant maternal protective effect on cleft lip/palate risk (LRT p=0.008), with homozygous carriers of the T allele showing reduced risk (RR=0.50, 95% CI 0.26-0.96). MTHFR rs1801133 demonstrated a protective effect in the low-folate supplementation subset (RR=0.60-0.44), and maternal folic acid supplementation ≥400 μg/day was associated with 39% reduction in cleft lip/palate risk.

This review examines 15 years of ischemic stroke susceptibility gene research, organized into three periods: early candidate gene studies (1985-1995) testing variants in hemostasis and homocysteine metabolism genes; expansion period with functional variants discovered from other diseases tested on larger stroke cohorts; and current GWAS-driven large-scale genotyping studies. Key findings include identification of susceptibility loci in CELSR1 (rs6007897, rs4044210 in Japanese populations), PITX2 (rs2200733, rs10033464), and other genes involved in lipid metabolism (APOA5, APOCIII, MLXIPL) and signal transduction (PDE4D, ALOX5AP), with evidence that alleles are often shared across diseases and that careful clinical stratification is critical.

A case-control study of 1,097 renal cell carcinoma (RCC) cases and 1,555 controls in Central and Eastern Europe examined common genetic variation in 5 folate metabolism genes. Variants in MTHFR (A222V rs1801133) and TYMS (IVS2-405C rs502396) were significantly associated with RCC risk, with the MTHFR variant increasing risk (OR=1.44) particularly in groups with low vegetable intake, while TYMS variant reduced risk (OR=0.73). The associations demonstrated significant gene-nutrient interactions with vegetable consumption.

Case-control study of 536 cleft lip with/without cleft palate (CLP) cases and 426 cleft palate only (CPO) cases in Ireland, testing four folate metabolism gene SNPs. MTHFD1 1958 G→A showed maternal risk associations with CPO (OR 1.50, p=0.02) and CLP (OR 1.38, p=0.03). MTHFR 677 C→T showed maternal risk for CPO (OR 1.50, p=0.03). MTHFR 1298 A→C and TC II 776 C→G showed no significant associations.

This pharmacogenetics study analyzed 28 SNPs in methotrexate (MTX) metabolism genes (SLC19A1/RFC1, ABCB1, FPGS, GGH) in two Spanish populations with rheumatoid arthritis (n=124 and n=194). Key findings: FPGS rs10987742 and rs10106 associated with MTX response (p=0.033, p=0.041); FPGS rs10106 also associated with MTX survival (p=0.005) and toxicity (p=0.021); ABCB1 rs868755, rs10280623, rs1858923 associated with toxicity (p=0.025, p=0.048, p=0.031). In the first study, MTHFR rs17421511 (p=0.024) and rs1476413 (p=0.0086) associated with response, DHFR rs1643650 (p=0.026) associated with response, ATIC rs16853826 associated with toxicity (p=0.039).

This pharmacogenetic study examined genetic variants in the folate metabolism and MTX transport pathways in rheumatoid arthritis patients receiving methotrexate monotherapy. Study 1 (n=124) identified rs17421511 and rs1476413 in MTHFR and rs1643650 in DHFR as significantly associated with MTX treatment response (p=0.024, p=0.0086, p=0.026 respectively), and rs16853826 and rs10197559 in ATIC as associated with toxicity (p=0.039). Study 2 (n=194) found rs10106 and rs10987742 in FPGS associated with response, and rs868755, rs10280623, rs1858923 in ABCB1 associated with toxicity, with rs10106 also associated with longer MTX monotherapy survival.

Case-control study of 365 HCC patients and 457 controls examining MTHFR and TYMS gene polymorphisms. Low-activity MTHFR variants (C677T rs1801133, A1298C rs1801131) were each associated with 30-50% reduced HCC risk (OR 0.46-0.70). TYMS 3'UTR deletion variant (rs16430) showed 50% risk reduction (OR 0.50, 95% CI 0.33-0.76). Monotonic dose-dependent protection observed with increasing number of mutant alleles across loci (p-trend=0.003).