Online Supplementary Appendix METHODS Study subjects We analysed samples from three independent case-control groups. As described previously,24 the Shanghai group consisted of 602 patients with CHD and 660 patient-matched healthy controlswho were enrolled between August 2008 and February 2011 from the Children’s Hospital of Fudan University (Shanghai, China). The Shandong group consisted of 735 patients with CHD and 564 controls recruited between August 2008 and January 2011 fromthe Cardiovascular Disease Institute, General Hospital of Jinan Military Command (Jinan, Shandong Province, China). To determine whether population stratification might affect our results, we performed principle component analyses using 16 ancestry-informative markers in the Shanghai and Shandong groups. No significant difference was observed in ancestry-informative biomarkers among the tested cases and controls. The Jiangsu group consisted of 1,003 patients with CHD and 1,046 controls recruited from the First Hospital of Nanjing Medical University (Nanjing, Jiangsu Province, China) between March 2006 and July 2008. All of the controls were non-CHD outpatients during the same time period and from the same geographic area who were matched to the affected individuals by age and sex. All of the subjects were genetically unrelated ethnic Han Chinese. Patients with CHD who had structural malformations involving another organ system or a positive family history of CHD in a first-degree relative (parents, siblings and children) were excluded. We classified the 2,340 CHD cases into seven broad classes. In particular, 386 (16.5%) had conotruncal defects, 1,652 (70.6%) exhibited septation defects, 47 (2%) exhibited left ventricular outflow tract obstruction (LVOTO), 75 (3.2%) exhibited right ventricular outflow tract obstruction (RVOTO), 14 (0.6%) exhibited anomalous pulmonary venous return (APVR), 34 (1.5%) exhibited complex CHD, and 132 (5.6%) had other CHD defects (Table S1). To screen for non-coding variants in the MTR gene, 32 unrelated individuals, (16 patients with CHD and 16 controls) from the Shanghai and Shandong groups were randomly selected for resequencing. For the quantitative RT-PCR assays and promoter methylation analysis, 28 in vivo human cardiovascular tissue samples were obtained from patients with CHD who had undergone heart catheterisation or a cardiac operation between January 2010 and May 2010 in the Cardiovascular Disease Institute, General Hospital of Jinan Military Command (Jinan, Shandong Province, China). All of the study protocols were reviewed and approved by the local medical ethics committee, and written consent was obtained from parents and/or patients prior to commencing the study. SNP identification and genotyping Genomic DNA was isolated from venous blood using conventional reagents. The MTR non-coding region from -2,055 to +510 bp (2,565 bp, chr1: 235023287-235025851, NC_000001.9, GI: 89161185) and the fragment containing the entire 3’UTR (3,186 bp, chr1: 235127516-235130702, NC_000001.9, GI: 89161185) were amplified using PCR from 32 unrelated individuals who were randomly selected from both the Shanghai and Shandong groups for variant screening using sequencing. We identified 4 common polymorphisms within the screened regulatory region of MTR gene with the minor allele frequency (MAF) >0.1, including rs28372871 in the promoter, rs2853522, rs1131450, and rs1804742 in the 3’UTR. We genotyped all 4 SNPs in 270 CHD cases versus 552 controls in the Shanghai group and found that the genotype distribution of rs28372871 and rs1131450 was statistically different between CHD and control subjects in genetic codominant model. The minor allele at each variant was associated with an increased risk of CHD (Table S2). Similar results were obtained in the validation study, which compared 259 cases with 324 controls in the Shandong group (Table S2). Although the rs28372871 was not related to CHD in codominant model (P=0.064), it showed significant association with CHD in recessive model (P=0.022), the GG genotype could lead to 1.56-fold increase of CHD risk (OR=1.56, 95%CI=1.07-2.29). All these results indicated that rs28372871 and rs1131450 were related to CHD risk. To further validate these association, we genotyped rs28372871 and rs1131450 in expanded cohorts with 602 cases versus 660 controls in the Shanghai group and 735 cases versus 660 controls in Shandong group. In addition, 1003 cases versus 1046 controls sampled from Jiangsu were also added for validation. Direct dye terminator sequencing of the PCR products was performed using the ABI Prism BigDye system according to the manufacturer’s instructions (ABI, Foster City, CA). Selected SNPs were genotyped using SNaPshot analysis (ABI). Sequencing and genotyping samples were processed on an ABI 3730 automated sequencer and analysed using SeqMan and Peakscan, respectively. All of the DNA sequences of primer pairs are listed in Table S7. Plasmid Construction To construct the MTR promoter reporter plasmid, a 1,304-bp fragment from -1267 to +37 of MTR containing the T allele of the -186T>G SNP was amplified from genomic DNAusing PCR. The PCR products were cloned into the MluI and BglII restriction sites of the pGL3-Basic vector (Promega, Madison, WI), in which the firefly luciferase gene was usedas a reporter. The corresponding G allele plasmid was generated using site-directed mutagenesis using the MutanBEST kit (Takara, Berkeley, CA) to ensureuniform backbone sequence. We verified all of the recombinant clones using DNA sequencing. To construct the MTR 3’UTR reporter plasmid, we amplified an 878-bp fragment of the 3’UTR of the MTR gene containing the G allele of the +905G>A SNP from genomic DNA. The PCR products were subsequently digested using XhoI and BamHI and cloned into the 3’UTR of the Renilla luciferase gene of the psiCHECK-2 vector (Promega). The Renilla luciferase gene was used as a reporter, and its expression could be normalised to the firefly luciferase signal. The corresponding A allele was generated using the MutanBEST kit. The primers utilised are shown in the Table S7. Cell Culture and Transfection For the 5-aza-20-deoxycytidine (5-Aza) (Sigma–Aldrich, St.Louis, MO) treatment, which causes DNA demethylation or hemidemethylation, 2×105 cells were seeded in a six-well plate in 3 ml of medium. After 24 hours of incubation, the medium was removed, and the cells were incubated in 3 ml of fresh medium containing 10 mM 5-Aza for 24 hours. After treatment, the medium was removed, the cells were subjected to an additional 24 hours of incubation in 3 ml of fresh medium without 5-Aza, and total RNA was extracted. In the control well, 5-Aza was replaced with DMSO, and the medium was changed daily. For the MTR promoter study, 1×105 HEK-293, H9C2 or HCM cells were transfected with 1 µg of each MTR promoter reporter plasmid and 20 ng of the pRL-TK plasmid (Promega) as a normalizing control. Alternatively, the cells were additionally co-transfected with 50 ng of the pcDNA3.1-USF-2 expression plasmid or equivalent amounts of empty pcDNA3.1 vector. Lipofectamine 2000 (Invitrogen, Carlsbad, CA) was used for all of the transfections, according to the manufacturer’s instructions. After another 24 hoursof culture, the transfected cells were lysed, and 40 µl of supernatant was assayed for luciferase activity using the Dual-Luciferase Reporter Assay System (Promega). The relative reporter activity was obtained by normalisation of the firefly activity to Renilla activity. Each assay was performed intriplicate, and each experiment was performed at least three times. For the MTR 3’UTR study, 1×105 HEK-293, H9C2 or HCM cells were transfected with 1 µg of each MTR 3’UTR reporter plasmid. For candidate microRNA screening, 5×104 H9C2 cells were seeded in a 96-well culture plate in DMEM that was supplemented with 10% FBS. The cells were co-transfected with 100 ng psiCHECK-G/A plasmid and 300 ng microRNA expression vector using Lipofectamine 2000, in accordance with the manufacturer’s protocol. To confirm the interaction between the MTR 3’UTR and the candidate microRNAs, HEK-293, HCM and H9C2 cells were co-transfected with 100 ng psiCHECK G/A plasmid and 0 ng, 150 ng, 300 ng, 450 ng or 600 ng of the candidate microRNA expression vector. In the siRNA assays, HEK-293 cells were co-transfected with 200 ng psiCHECK G/A plasmid and 800 ng microRNA inhibitors. At 24 hours after transfection, Firefly and Renilla luciferase activities were measured using a dual-luciferase assay. The relative reporter activity was obtained by normalisation to the Renilla activity. We performed luciferase assays in triplicate each time for three independent transfection experiments. EMSA Nuclear proteins were extracted from HEK-293 cells using NE-PER nuclear and cytoplasmic extraction reagents (Pierce, Rockford, IL). Duplex oligonucleotide probes representing the -186 T or G alleles (sequences listed in the Table S7) were labelled with biotin. The EMSAs were performed using a Light Shift Chemiluminescent EMSA kit (Pierce) according to the manufacturer’s protocols. Briefly, 1 pmol of biotin-labelled duplex oligonucleotides bearing either the -186 T or G allele was incubated with 8 μg of nuclear extracts for 20 minutes in 10 × binding buffer supplemented with 1 µg/µl poly (dI·dC), 50% glycerol and 1% Nonidet P-40. Unlabelled probes at 5-, 10- or 100-fold molar excesses, as indicated, were added to the reaction for competition. The reaction mixture was then electrophoresed on a native 6% polyacrylamide gel and transferred to a positive nylon membrane. The detection of biotin-labelled DNA was performed using stabilised streptavidin-horseradish peroxidase conjugate (Pierce) and exposed to X-ray film. Surface plasmon resonance (SPR) analysis SPR analysis was performed using the ProteOn XPR36 Protein Interaction Array System (Bio-Rad Laboratories, Hercules, CA), an SPR technology-based imaging optical biosensor. Biotinylated duplex oligonucleotide probes representing the -186 T or G allele (sequences listed in the Table S7) were immobilised on the streptavidin-modified surface in different channels from DNA solutions at a fixed concentration (400 nM) to ensure identical surface density. Nuclear extracts from HEK-293 cells or purified USF-2 protein were diluted in PBST (10 mM Na-phosphate, 150 mM NaCl and 0.005% Tween 20, pH 7.4) to different concentrations and then pre-incubated with non-specific DNA for 15 minutes before being passed across the DNA-immobilised surface. Non-biotinylated competitors at a four-fold excess were used for competition assays. All of the binding measurements were performed using PBST as the continuously running buffer at room temperature. The relative binding responses were determined by measuring changes in refractive index levels before and after the addition of nuclear proteins. After each cycle, 1 M NaCl and 50 mM NaOH were consecutively injected to regenerate the sensor surface. The results are presented as a sensogram and converted using BIA-evaluation software. SPR analysis was also utilised to quantify the binding affinity between 3’UTR RNA and microRNAs. Cytoplasmic proteins were extracted using NE-PER nuclear and cytoplasmic extraction reagents. The single-stranded RNA probes representing +905 G or A, miR-608 or miR-1293 (sequences listed in the Table S7) were synthesised by GenePharma Co., Ltd. (Shanghai, China). After each reaction cycle, 1 M NaCl and 50 mM NaOH were consecutively injected to regenerate the sensor surface. Chromatin immunoprecipitation (ChIP) assays The ChIP assays were conducted using the EZ ChIP Kit (Upstate Biotechnology, Lake Placid, NY). Briefly, HEK-293 cells and cardiovascular tissue samples from two patients heterozygous for -186T>G in the MTR promoter were cross-linked with 1% formaldehyde for 10 minutes. The DNA was fragmented to a mean length of 200 to 1000 bp using sonication. For immunoprecipitation, sheared chromatin was incubated with antibodies against USF-1/2 or non-specific rabbit IgG (Santa Cruz Biotechnology, Santa Cruz, CA) for 12 hours at 4°C. The identity and quantity of the DNA fragments were determined using PCR and quantitative real-time PCR. To further investigate the difference in binding affinity between the T and G alleles of the SNP -186T>G, the amounts of the two alleles were quantified using SNaPshot from the ChIP input, and the products were treated with the USF-1/2 antibody. All of the primers that were used are listed in Table S7. Quantitative real-time PCR Total RNA was extracted from human cardiovascular tissue samples preserved in RNAlater (Qiagen, Valencia, CA) using the miRNeasy Mini Kit (Qiagen) and then converted to cDNA using random hexamers, oligo(dT) primers and Moloney murine leukaemia virus reverse transcriptase (Takara). MTR hnRNA and mRNA levels were measured using quantitative real-time PCR using the ABI Prism 7900 sequence detection system (Applied Biosystems, Foster City, CA), with GAPDH as an internal reference gene. The reaction mixture contained 0.1 M of each primer, 2× SYBR Green PCR Master Mix (TaKaRa) and 1 µl of cDNA (1:10 dilution). The primers that were used are listed in Table S7. The identification and quantification of miRNA were performed using the Hairpin-it miRNA qPCR Quantitation Kit (GenePharma, Shanghai, China). Each reaction was performed in triplicate. Bisulfite sequencing The treatment of genomic DNA with bisulfite was performed using the EZ DNA Methylation-Gold kit (ZYMO Research, Los Angeles, CA) according to the manufacturer’s instructions. The core region of the MTR promoter from -220 bp to +25 bp from its transcriptional start site contains 22 CpG sites and was amplified in a 50 μl reaction mixture containing 20 ng of bisulfite-treated DNA, 75 pmol of primer (sequence listed in Table S7), 2.5 mM of dNTPs and 1 unit of Hotstart Taq polymerase (Takara). The PCR products were separated using agarose gel electrophoresis and purified using the QIAquick Gel Extraction Kit (Qiagen). The resulting fragment was cloned into pMD T-19 (Takara). After bacterial amplification of the cloned PCR fragments, 10 clones from 28 different PCR assays were subjected to direct sequencing on an ABI Prism 3770 sequencer (Applied Biosystems). Plasma homocysteine detection EDTA-plasma samples were obtained from fasting undergraduate volunteers in the early morning, centrifuged immediately and stored in a -80C freezer until being subjected to homocysteine detection. The Axis® Homocysteine Enzyme Immunoassay (EIA) Kit (Axis-Shield, Norton, MA) was used to determine plasma homocysteine levels, according to the manufacturer’s instructions. Each test was duplicated, and the mean level was used for further analysis. Statistical analysis Differences in qualitative demographic features and allelic or genotypic frequencies between the CHD cases and the controls were compared using the χ2 test. Hardy-Weinberg equilibrium was also tested using the χ2 test in the controls. To evaluate the associations between genotypes and CHD risk, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression analysis with adjustment for age and sex. Multiple testing of association results was conducted by Bonferroni correction. As there are four SNPs being tested under 5 genetic models (additive, dominant, recessive, codominant and overdominant), the significance level was adjusted to 0.05/(4×5)=0.0025. A meta-analysis of three cohorts was performed using SAS software (version 9.1.3). The estimation of haplotype frequency and the analysis of associations between different haplotypes and CHD risk were performed using the SNPStats web tool (http://bioinfo.iconcologia.net/snpstats/start.htm) with adjustment for age and sex. To investigate gene interactions between MTRR and MTR, a logistic regression model and multifactor dimensionality reduction analysis were performed in R language (version 2.13.1), and epistasis analysis in PLINK (version 1.1) was used for the statistical analysis. The linear regression analysis of the relation between methylation level and MTR expression was performed in Microsoft Office Excel 2007. The quantitative variables are given as the mean ± standard error (SE). The differences between the two groups were evaluated using Student's t-test, and the differences between three or more groups were evaluated using one-way anova test. Both Student’s t-test and one-way anova test were performed using SPSS 15.0 software (SPSS, Chicago, IL). All of the statistical tests were two-tailed, with P<0.05 set as the significance level. Table S1.Demographic characteristics in CHD cases and controls Variable Cases No. % N=602 6.21±0.30 Controls No. % N=660 5.95±0.19 P value* Stage 1, Shanghai Group Age, years (mean±SE) 0.46 Gender 0.10 Male 332 55.1 394 59.7 Female 270 44.9 266 40.3 Stage 2, Shandong Group N=735 N=564 Age, years (mean±SE) 6.63±0.25 7.09±0.14 0.14 Gender 0.85 Male 365 49.7 283 50.2 Female 370 50.3 281 49.8 Stage 3, Jiangsu Group N=1003 N=1046 Age, years (mean±SE) 6.78±0.31 6.72±0.29 0.86 Gender 0.73 Male 528 52.6 558 53.3 Female 475 47.4 488 46.7 Combined samples N=2340 N=2270 Age, years (mean±SE) 6.59±0.17 6.59±0.15 0.99 Gender 0.16 Male 1225 52.4 1235 54.4 Female 1115 47.6 1035 45.6 CHD classification Ⅰ Conotruncal defects 386 16.5 Septation defects 1652 70.6 LVOTO 47 2.0 RVOTO 75 3.2 APVR 14 0.6 Complex CHDs 34 1.5 Other CHDs 132 5.6 CHD classification Ⅱ Isolated CHD 2025 86.5 Nonisolated CHD 315 13.5 Isolated CHD phenotype VSD 1220 52.1 ASD 235 10.0 TOF 291 12.4 *The comparison of age was performed by student T test, and thecomparison of gender was performed by 2-tailed χ2 test. Date shown in the row of age are means±SE. TableS2. The genotype frequency of the 4 identified MTR SNPs in CHD patients and controls SNP Group Shanghai rs28372871 Shandong Shanghai rs2853522 Shandong Shanghai rs1131450 Shandong Shanghai rs1804742 Shandong Genotype Control Case T/T 182 (33%) 77 (28.5%) G/T 275 (49.8%) 116 (43%) G/G 95 (17.2%) 77 (28.5%) T/T 89 (27.5%) 60 (23.2%) G/T 169 (52.2%) 125(48.3%) G/G 66 (20.4%) 74 (28.6%) G/G 155 (28.1%) 81 (30%) G/T 289 (52.4%) 128(47.4%) T/T 108 (19.6%) 61 (22.6%) G/G 90 (27.8%) 63 (24.3%) G/T 164 (50.6%) 145 (56%) T/T 70 (21.6%) 51 (19.7%) G/G 377 (68.3%) 150(55.6%) G/A 164 (29.7%) 96 (35.6%) A/A 11 (2%) 24 (8.9%) G/G 206 (63.6%) 146(56.4%) G/A 107 (33%) 93 (35.9%) A/A 11 (3.4%) 20 (7.7%) G/G 473 (85.7%) 228(84.4%) G/A 76 (13.8%) 36 (13.3%) A/A 3 (0.5%) 6 (2.2%) G/G 269 (83%) 220(84.9%) G/A 51 (15.7%) 35 (13.5%) A/A 4 (1.2%) 4 (1.5%) *Genotype frequencies in case/control were compared using χ2 test; ** P value for Hardy-Weinberg equilibrium test in the control subjects; ***P value in Recessive model. P value* HWP** 0.0011 0.66 0.022*** 0.43 0.38 0.23 0.43 0.82 <0.0001 0.17 0.036 0.6 0.11 1 0.72 0.32 Table S3. Associations between selected folate-pathway variants of coding region and CHD in 3 separated case-control studies. GenoHWP* Case Control OR (95% CI)* P value** type ** A/A 406 (67.4%) 454 (68.8%) 1.00 ShangHai C/A 167 (27.7%) 187 (28.3%) 1.01 (0.79-1.30) 0.21 1.00 C/C 29 (4.8%) 19 (2.9%) 1.69 (0.93-3.07) A/A 562 (76.5%) 432 (76.6%) 1.00 ShanDong C/A 146 (19.9%) 124 (22%) 0.90 (0.69-1.19) 0.029 1.00 C/C 27 (3.7%) 8 (1.4%) 2.58 (1.16-5.74) A/A 695 (69.3%) 707 (67.6%) 1.00 JiangSu C/A 254 (25.3%) 308 (29.4%) 0.84 (0.69-1.02) 0.0045 0.83 C/C 54 (5.4%) 31 (3%) 1.79 (1.12-2.78) C/C 183 (30.4%) 203 (30.8%) 1.00 ShangHai C/T 310 (51.5%) 323 (48.9%) 1.04 (0.81-1.34) 0.55 0.81 T/T 109 (18.1%) 134 (20.3%) 0.88 (0.64-1.22) C/C 231 (41%) 231 (41%) 1.00 ShanDong C/T 260 (46.1%) 260 (46.1%) 1.04 (0.82-1.31) 0.56 1.00 T/T 73 (12.9%) 73 (12.9%) 1.21 (0.86-1.70) C/C 311 (31%) 314 (30%) 1.00 JiangSu C/T 473 (47.2%) 514 (49.1%) 0.92 (0.76-1.17) 0.67 0.8 T/T 219 (21.8%) 218 (20.8%) 1.01 (0.79-1.30) A/A 334 (55.5%) 375 (56.8%) 1.00 ShangHai G/A 227 (37.7%) 235 (35.6%) 1.10 (0.87-1.40) 0.61 0.12 G/G 41 (6.8%) 50 (7.6%) 0.92 (0.59-1.43) A/A 431 (58.6%) 309 (54.8%) 1.00 ShanDong G/A 243 (33.1%) 217 (38.5%) 0.80 (0.63-1.01) 0.10 1.00 G/G 61 (8.3%) 38 (6.7%) 1.16 (0.75-1.78) A/A 543 (54.1%) 610 (58.3%) 1.00 JiangSu G/A 390 (38.9%) 366 (35%) 1.20 (1.00-1.45) 0.15 0.15 G/G 70 (7%) 70 (6.7%) 1.12 (0.78-1.58) A/A 513 (85.2%) 567 (85.9%) 1.00 ShangHai G/A 80 (13.3%) 87 (13.2%) 1.01 (0.73-1.40) 0.66 0.25 G/G 9 (1.5%) 6 (0.9%) 1.61 (0.57-4.56) A/A 627 (85.3%) 459 (81.4%) 1.00 ShanDong G/A 103 (14%) 97 (17.2%) 0.78 (0.57-1.05) 0.11 1.00 G/G 5 (0.7%) 8 (1.4%) 0.46 (0.15-1.42) A/A 891 (88.8%) 913 (87.3%) 1.00 JiangSu G/A 104 (10.4%) 129 (12.3%) 0.83 (0.63-1.09) 0.077 0.25 G/G 8 (0.8%) 4 (0.4%) 2.04 (0.62-6.67) * Adjusted for age, sex; ** Genotype frequencies in case/control were compared using χ2 test; *** P value for Hardy-Weinberg equilibrium test in the control subjects. MTR c.2756 A>G MTRR c.66 A>G MTHFR c.677 C>T MTHFR c.1298 A>C SNP Group Table S4. MTR haplotype analysis between CHDs and controls. No OR (95 CI)* P value$ 0.4766 1.00 - 0.2906 0.2885 1.15 (1.03-1.28) 0.01 0.0355 0.0438 0.0396 1.47 (1.14-1.89) 0.019 0.1684 0.221 0.1952 1.52 (1.35-1.72) 2.4×10-12 -186 +905 Freq Freq Freq T>G G>A (Control) (Case) (Total) 1 T G 0.5094 0.4447 2 G G 0.2866 3 T A 4 G A * Adjusted by age and gender;$ P value for differencesof haplotype distribution between case and control subjects. Table S5. The cumulative effect of genotypes on CHD at variant -186T>G and +905G>A Genotype* Case Control OR (95% CI) P value P trend TT/GG 535(22.9%) 591(26.0%) 1.00 TG/GG 549(23.5%) 651(28.7%) 0.93 (0.79-1.1) 0.39 GG/GG 215(9.2%) 181(8.0%) 1.31 (1.04-1.65) 0.02 TT/GA 62(2.6%) 64(2.8%) 1.07 (0.74-1.54) 0.73 TG/GA 452(19.3%) 465(20.5%) 1.08 (0.90-1.28) 0.41 7.61×10-15 GG/GA 329(14.1%) 239(10.5%) 1.52 (1.24-1.86) 6.29×10-5 TT/AA 20(0.9%) 15(0.7%) 1.49 (0.75-2.93) 0.25 TG/AA 51(2.2%) 18(0.8%) 3.13 (1.81-5.43) 4.76×10-5 GG/AA 127(5.4%) 46(2.0%) 3.04 (2.13-4.35) 1.04×10-9 The controls used were the total 2270 combined controls; *Genotype combination: -186T>G/+905G>A. Boldface indicates statistical significance. Table S6. Stratification analysis of MTR variants genotypes according to CHD classification and phenotype. Variable Case number P value rs28372871 Association [OR (95% CI)]* TG vs. TT GG vs. TT 0.94 (0.72-1.21) 1.45 (1.08-1.94) 1.01 (0.87-1.18) 1.62 (1.36-1.93) CHD Classification Ⅰ Conotruncal defects Septation defects 386 0.005 -8 1652 2.55×10 LVOTO 47 0.003 1.84 (0.78-4.36) 4.13 (1.71-9.93) RVOTO 75 0.14 0.78 (0.45-1.35) 1.39 (0.76-2.52) APVR 14 0.04 1.06 (0.35-3.18) -- Complex CHDs 34 0.25 2.07 (0.83-5.15) 1.67 (0.56-5.00) Other CHDs 132 0.46 1.06 (0.69-1.61) 1.34 (0.82-2.19) Isolated CHD 2025 1.72×10-9 0.99 (0.86-1.15) 1.56 (1.32-1.85) Nonisolated CHD 315 0.028 1.11 (0.83-1.49) 1.54 (1.11-2.13) 235 0.005 0.98 (0.70-1.37) 1.65 (1.14-2.39) 1220 6.79×10-8 1.01 (0.85-1.20) 1.61 (1.33-1.96) 291 0.011 0.94 (0.70-1.27) 1.48 (1.06-2.05) GA vs. GG AA vs. GG CHD Classification Ⅱ Detailed phenotype ASD (atrial septal defect) VSD (ventricular septal defect) TOF (tetralogy of Fallot) rs1131450 CHD Classification Ⅰ 386 1.19×10-5 1.21 (0.96-1.53) 2.96 (1.93-4.52) 1652 9.48×10-12 1.20 (1.05-1.37) 2.73 (2.05-3.64) LVOTO 47 0.16 1.37 (0.74-2.54) 3.00 (1.02-8.89) RVOTO 75 0.66 0.90 (0.54-1.49) 1.51 (0.53-4.29) APVR 14 0.61 1.03 (0.34-3.07) -- Complex CHDs 34 0.86 1.21 (0.60-2.45) 0.91 (0.12-6.84) Other CHDs 132 0.0002 1.42 (0.97-2.08) 4.10 (2.22-7.58) Isolated CHD 2025 2.85×10-13 1.21 (1.06-1.37) 2.76 (2.09-3.64) Nonisolated CHD 315 0.0007 1.19 (0.93-1.53) 2.63 (1.64-4.21) ASD (atrial septal defect) 235 0.070 1.15 (0.86-1.54) 2.05 (1.13-3.71) VSD (ventricular septal 1220 5.48×10-12 1.21 (1.04-1.41) 2.97 (2.19-4.02) 291 0.0003 1.31 (1.01-1.70) 2.75 (1.69-4.48) Conotruncal defects Septation defects CHD Classification Ⅱ Detailed phenotype defect) TOF (tetralogy of Fallot) The controlswerethe total 2270 controls; *Adjusted for age, sex. Table S7. DNA sequence of all used primer pairs SN Primer Name Sequence (5’-3’) 1 MTR-F1 TCACTGCCCCTTTAGGCACT 2 MTR-R1 GGAAAAGCAAATGCATCCAGA 3 MTR-F2 GGTCTTGGTAAGAATGTGATACGC 4 MTR-R2 TCTCCACACTCTACAAACAAGAATGA 5 MTR-F3 CACCCCCATATGGTAATTCAGAG 6 MTR-R3 CTTGGTGTCGGCCTAGCAG 7 MTR-F4 TAACCGCGCTCTGAAAGGTT 8 MTR-R4 TCGGACAAAGAGTGGAGCAA 9 MTR-F5 TGGCTGAGGTTGAGAAATGG 10 MTR-R5 GGGCAAATGGCTTCAGTGTT 11 MTR-F6 CGGGGAAGGTGTAGCTCTGT 12 MTR-R6 TCCTCCCTTGCTTCTTCGTC 13 MTR-F7 TGGTGGTGGCAATAGTCAGG 14 MTR-R7 CAGAATTGACTTAACCATCTTGTCC 15 MTR-F8 CCTTACCTGGTGATAAGTTCCAAA 16 MTR-R8 GACAGACATACATTTCACTTTTTCCA 17 MTR-F9 CCCACCTGTATGTCCAGCAA 18 MTR-R9 TCCTGCCCCTCACCTTTCTA 19 rs28372871-F AACGCCTACTACAACCCTAAAA 20 rs28372871-R AGTTCTGCGCTCAATCTATCC 21 rs2853522-F GGGTGCCTTAAAAATAACAACAACA 22 rs2853522-R TGGCCTCCTAGATTCCACTG 23 rs1131450-F CATGCCATTCTCCTGCCTCA 24 rs1131450-R TGCCCACTTGTCCAACTCC 25 rs1804742-F GGTGGTGGCAATAGTCAGGA 26 rs1804742-R CCCACATGAATAGCCATTGTTC 27 rs1805087-F TTTCAGTGTTCCCAGCTGTTAGAT 28 rs1805087-R AAACTAGGATCATAAAAAACAGTCACATT 29 rs1801394-F GGAAACACAGATTCAAGCCCAA 30 rs1801394-R CCCAACCAAAATTCTTCAAAGC 31 rs1801131-F TTTGCCTCCCTAAGCCCTTC 32 rs1801131-R GGGCCTCCAGACCAAAGAGT 33 rs1801133-F TCAGCGAACTCAGCACTCCA 34 rs1801133-R TCTTCATCCCTCGCCTTGAA 35 rs28372871-typing CGGCTGCGAGGAGCTCG 36 rs2853522-typing TAGTCTTCGAAAACCAGAAGCAGG 37 rs1804742-typing GCCCTTATTTTGTTCCCCTGCTCA 38 rs1131450-typing AAATTAGCCGGGTGTGGTGG 39 rs1805087-typing CACTTACCTTGAGAGACTCATAATGG 40 rs1801394-typing AAAGGCCATCGCAGAAGAAAT 41 rs1801131-typing GGGGAGGAGCTGACCAGTGAAG 42 rs1801133-typing GCTGCGTGATGATGAAATCG Purpose PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR/Sequence PCR PCR PCR PCR PCR PCR PCR PCR PCR PCR PCR PCR PCR PCR PCR PCR Genotyping Genotyping Genotyping Genotyping Genotyping Genotyping Genotyping Genotyping 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 MTR-promter -F ATGGCGACGCGTCGCCATCTCATTCCTCCCTCCCTTCTTT Construct MTR-promter -R ACTGGAAGATCTTCCAGTCCTTGGTGTCGGCCTAGCAG Construct MTR-UTR -F CACAACTCGAGCAGAACTCCCTTTGGCAAAAGGCAT Construct MTR-UTR -R AAGGATCCCTTCATTTGTTCCTCCCTTGCTTCT Construct -186 T-F GCGAGGAGCTCGTGCAGACCAATCAC EMSA/SPR -186 T-R GTGATTGGTCTGCACGAGCTCCTCGC EMSA/SPR -186 G-F GCGAGGAGCTCGGGCAGACCAATCAC EMSA/SPR -186 G-R GTGATTGGTCTGCCCGAGCTCCTCGC EMSA/SPR +905 G-RNA GGACUACAGGUGCCCGCCACCACACCCGGCU SPR +905 A-RNA GGACUACAGGUGCCCACCACCACACCCGGCU SPR miR-485 AGAGGCUGGCCGUGAUGAAUUC SPR miR-608 AGGGGUGGUGUUGGGACAGCUCCGU SPR miR-1293 UGGGUGGUCUGGAGAUUUGUGC SPR MTR -186 F ACAGCAGGTGATTGGTTGA CHIP MTR -186 R AGCCCCGCAGACATTTAG CHIP MTR-nascent-F CGGGAGAAGCTAAACGAAGA RT-qPCR MTR-nascent-R GGAACCTGGGAATACTTTACCTT RT-qPCR MTR-mRNA-F CGCAACCCGAAGGTCTGAA RT-qPCR MTR-mRNA-R TTCTTCGTTTAGCTTCTCCCG RT-qPCR GAPDH-mRNA-F GAAGGTGAAGGTCGGAGTC RT-qPCR GAPDH-mRNA-R GAAGATGGTGATGGGATTTC RT-qPCR MTR-methy-F GGGTTAAATAGTAGGTGATTGGTTG Methylation MTR-methy-R TTAATATCGACCTAACAACCAAACA Methylation Figure S1. The MTR -186G allele attenuates transcription factor binding affinity. (A) EMSAs revealed that, compared with the major T allele probe, the minor G allele oligonucleotide probe had lower affinity for nuclear proteins of Hek-293 cells; (B) SPR analysis comparing the binding affinity of nuclear extracts or purified recombinant USFprotein to DNA probes containing either the -186T allele or G allele; (C) Competition SPR assays performed in the presence of a five-fold excess of non-biotinylated A allele or C allele probe; (D) ChIP assays using Hek-293 cells and cardiovascular tissue samples. The amount of immunoprecipitatedMTR promoter was measured using quantitative real-time PCR; (E) The amount of the two alleles was quantified using SNaPshot from CHIP input and products treated with the USF-1/2 antibody. FigureS2. USF (upstream stimulatory factor) was computationally predicted as the possible target transcription factor at position -186T>G, and the results showed that, when the major T was substituted with the minor G, USF would lose the original binding site. FigureS3. 5-Aza treatment causes increased MTR gene transcription. Hek-293 cells were treated with medium containing 10µM 5-Aza for 72 hours. MTRhnRNA and mRNA levels were quantified using quantitative real-time PCR. Data shown are mean±SE of three experiments, and each experiment was performed in triplicate. FigureS4. +905G>A variant can affect the compensatory base pair binding between miR-608(A), miR-1293(B) and mRNA. The direct SPR assays confirmed that the +905A allele bound to microRNA more strongly than the G allele. KD (Affinityequilibrium constant)=KD(dissociation constant) /KA(association constant). FigureS5. miR-485, miR-608 and miR-1293 decrease MTR expression by repressing translation. Data shown are mean±SE.(A)The ratio of MTRmRNA/hnRNA was compared, and we found no significant difference among different +905G>A genotypes. This result implied that MTR was not regulated bymicroRNAs in the post-transcription stage. (B) Hek293 cells were co-transfected with the psiCHECK2-A construct and a microRNA expression vector, and mRNA and protein levels of Rluc were quantified using real-time quantitative PCR and a luciferase assay, respectively. (C) Hek293 cells were transfected with microRNA and microRNA inhibitors. After 48 hours of culture, MTR mRNA and protein levels were determined usingreal-time quantitative PCR and western blotting. FigureS6.The human homocysteine concentration was significantly different among the groups with different genotype in variants -186T>G and+905G>A of MTR, andc.677C>T of MTHFR, and eachminor allele of the above variants statistically contributed to the elevated homocysteineconcentrations.Data shown are mean±SE.