INTRODUCTION:

The MTHFR gene produces the rate-limiting enzyme of the methyl cycle, Methylenetetrahydrofolate reductase (MTHFR). As a co-substrate for the re-methylation of homocysteine to methionine and the production of tetrahydrofolate, MTHFR catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. Methionine is needed for the synthesis of amino acids and proteins, and the production of tetrahydrofolate is crucial for the synthesis of macromolecules (DNA and RNA) required for cell division^1,2.

Particularly in individuals with folate deficiency, genetic mutations in the MTHFR gene may cause dysfunction or inactivation of this enzyme, resulting in modestly elevated homocysteine levels^3,4.

The short arm of chromosome 1 contains the genomic locus for the MTHFR gene (1p36.2)². This gene's DNA sequence is around 2.2 kilobases (kb) long and has 12 exons⁵. Severe enzymatic deficits are linked to 109 variants in the MTHFR gene⁶. While the C677T (thermolabile alanine/valine) and the A1298C are two frequent polymorphisms that are linked to decreased enzyme activity⁷.

Exon 4 contains the C677T polymorphism, which converts codon 222 from alanine to valine. The MTHFR cofactor flavin adenine dinucleotide binds to bases in this region (FAD). The MTHFR C677T genotype exhibits 30% less in vitro MTHFR enzyme activity compared to the wild type. The second MTHFR polymorphism, A1298C, in exon 7 replaces glutamate at codon 429 with alanine. As a result of this polymorphism in the S-adenosyl methionine (SAM) regulatory domain, the MTHFR enzyme undergoes conformational changes that impact enzymatic activity⁵.

According to many studies^8-12, the amount of MTHFR activity may be a significant factor influencing the risk of developing some cancers, including bladder cancer, breast cancer¹³, colorectal cancer¹⁴, oral squamous cell carcinoma^15,16 and leukemia¹⁷. Other illnesses at risk include preeclampsia, Alzheimer's disease¹⁸, congenital heart problems, cleft palate, diabetes^19-20, hypotonia, schizophrenia²¹, depression, and birth deformities⁵.

It is unknown how prevalent the polymorphisms C677T and A1298C are in the coastal region of Syria. As MTHFR polymorphisms C677T and A1298C are associated with distinct diseases, the purpose of this study is to determine the frequency of these two variants (in this region of the country). This data will aid in the identification of population-based risk factors for a number of congenital and other anomalies associated with MTHFR polymorphism.

MATERIALS AND METHODS:

Study population:

After verbal consent seventy healthy men over the age of 40 from various regions of the country were comprised to our research sample. Samples were collected in the Central laboratory at Tishreen University Hospital (TUH).

Samples and DNA extraction:

Blood was drawn into vacutainer tubes anticoagulated with EDTA. DNA was extracted using the silica membrane column-based Generi Biotech extraction kit (Machkova 587; Hradec Králové, Czech Republic) as soon as it was collected.

Real-time PCR:

The gb HEMO MTHFR (C677T) and gb HEMO MTHFR (A1298C) (Machkova 587; Hradec Králové, Czech Republic) were used to identify the MTHFR gene polymorphisms C677T and A1298C, respectively.

Detection is based on real-time PCR with the use of fluorescently labelled probes, and specifically on the principle of allelic discrimination.

Statistical analysis:

Statistical analysis was performed using RStudio®, and results are expressed as percentage and allele frequency (calculated using the Hardy-Weinberg model).

RESULTS:

Our study included 70 healthy males from the Syrian coast aged over 40 years old. The results showed that for the MTHFR 677 polymorphism, the WT genotype (C/C) was the most prevalent (47.14%) with an overall carrier rate of 52.86% for the mutation (Table 1).

As for the MTHFR 1298 polymorphism, the WT genotype (A/A) was the most prevalent (44.29%). The overall carrier rate of the mutation was55.71%(Table 1).

Table 1: Genotype and Allele Frequency of the C677T and A1298C Polymorphisms among Syrians.

MTHFR 677 Genotypes (Total 70)			Alleles
C/C	C/T	T/T	C	T
33 (47.14%)	27 (38.57%)	10 (14.29%)	0.664	0.336
MTHFR 1298 Genotypes (Total 70)			Alleles
A/A	A/C	C/C	A	C
31 (44.29%)	25 (35.71%)	14 (20%)	0.622	0.378

We performed a gene combination analysis as the combined distribution of MTHFR C677T and A1298C variants is confirmed to have elevated risks for disease development such as cancer^22,23. The results are showed in (Table 2).

Table 2: Combined MTHFR C677T and A1298C Genotypes

C677T/A1298C	N (%)
CC/AA	8 (11.4)
CC/AC	12 (17.2)
CC/CC	13 (18.5)
CT/AA	14 (20)
CT/AC	12 (17.2)
CT/CC	1 (1.4)
TT/AA	9 (12.9)
TT/AC	1 (1.4)
TT/CC	0 (0)

According to the research, Tables 3 and 4 classify the distribution of the MTHFR C677T and A1298C alleles in various global populations.

Table 3: Allele Frequencies of MTHFR C677T Polymorphism Among Different Ethnic Populations

Population	Allele Frequency	T/T genotype frequency (%)	Reference
Mexican	0.586	34.8	24
Chinese	0.552	32.2	25
Italian	0.447	19.84	26
Italian	0.40	16	27
Asian	0.4	20	28
Japanese	0.38	11	29
Brazilian caucasian	0.373	10.3	1
European-White	0.362	9.6	28
Greek	0.353	8.1	30
Syrian	0.336	14.29	Present Study
Turkish	0.33	9.6	31
German	0.31	7.19	32
United Kingdom	0.293	12.28	33
dutch	0.26	5	34
ameridian	0.24	7.8	28
Lebanese	0.219	2.45	35
USA	0.21	5	36
Brazilian Black	0.2	1.45	1
lebanese	0.19	3.9	37
Jordanian	0.16	8	38
brazilian indian	0.114	1.2	1
Bahraini	0.11	2.63	35
African americans (USA)	0.11	0	39
tamilians (indian)	0.075	0	40
african black	0.052	0	28

Table 4: Allele Frequencies of MTHFR A1298c Polymorphism Among Different Ethnic Populations

Population	Allele Frequency	C/C Genotype Frequency (%)	Reference
lebanese	0.49	23.9	37
syrian	0.378	20	Present Study
tamilians (indian)	0.35	10	40
caucasian australian	0.34	11.8	41
Bahraini	0.34	7.3	42
caucasians	0.338	12	43
United Kingdom	0.333	9.65	33
Turkish	0.331	10	31
corsica island (france)	0.330	6	44
sweden	0.324	10.4	45
los angeles (white)	0.30	7.9	46
Italian	0.295	8.17	26
canadian	0.276	9	7
italian	0.268	4.6	47
hmong	0.265	7	48
italian	0.25	5.9	49
USA caucasians	0.25	4	50
african american	0.25	2.1	46
USA Hispanics	0.23	4	50
brazilian	0.21	7.2	51
Mexican	0.20	2.6	46
Chinese	0.176	3.8	52
Asian	0.16	1.9	46
Japanese	0.16	1.3	53
Indians	0.10	3	54

DISCUSSION:

The MTHFR polymorphisms' allele frequencies reveal racial and geographic differences among various groups. The Mexican¹⁴, Chinese¹⁵, Italian^16,17, Asian¹⁸, and Italian^16,17 populations had high allele frequencies for the C677T polymorphism, with Mexico having the highest allele frequency (0.586). In contrast, the allele frequencies for Black Africans from Zaire and Cameroon¹⁸, Tamilians³⁰, African Americans²⁹, and Bahrainis³² populations were noticeably low. Similar variations may be seen in the homozygous polymorphic T/T genotype frequency. The greatest rate (34.8%) is seen in the Mexican population, which is also high in the Chinese, Italian, and Asian populations. The T/T genotype frequency in the current sample (14.29%) was greater than in the Lebanese study²⁷.

In the current study, we examined two polymorphisms, MTHFR 677 and 1298, for the first time in a Syrian population. The allele frequency of MTHFR 677 was 0.336. In a healthy Serbian population, the MTHFR C677T allele frequency was reported to be 0.312, which was lower than the allele frequency in our study population and contained a variety of risk factors such as vascular disorders, thrombotic events, disorders of folate metabolism, genetic disorders, recurrent miscarriages, and obstetric complications⁴⁵.

Unlike the C677T polymorphism, the A1298C polymorphism showed comparable results to the Lebanese study³⁷ that had the higher allele frequency and frequency of the homozygous polymorphic C/C genotype among different ethnic populations. The present study came after the Lebanese study with the second highest allele frequency (0.378) and C/C genotype frequency (20%) worldwide. Our findings are comparable to those of the Tamilians (0.35)⁴⁰ and Bahraini Arabs (0.34)⁴². The 1298 C/C genotype is rarely found in Asians and Japanese, with the lowest frequency being found in Indians (0.1)⁵⁴. This result indicates that whites are more likely than other races to have the 1298C/C genotype.

17.14% of the patients in our research sample were heterozygous for both mutations, which is consistent with prior estimates of 15% to 20%^7,34. The percentage of doubly heterozygous individuals (677 C/T and 1298 A/C) was highest among Mexican (17.6%) and white women (15.1%) and lowest among African American (6.3%) and Asian (3.8%) women. The absence of individuals who were homozygous for both mutations is consistent with prior studies^7,34,55,56.

Weakness points to the present study include the small study population from a specific region of the country, and the exclusion of females in study population (as mentioned above white women had 15.1% of double heterozygous). Larger study with healthy volunteers of both sexes from different parts of the country is needed to generalize the present results to the Syrian population.

Diverse environmental factors, such as diets high or low in folate and vitamin B12, as well as the origin and relatedness of the world's various ethnic groups, appear to be responsible for the uneven distribution.

CONCLUSION:

In conclusion, the preponderance of the 1298 C/C genotype in the Syrian population is a significant finding that must be investigated in terms of clinical importance and reveals an additional genetic characteristic unique to the Syrian Coastal Area population.

CONFLICT OF INTEREST:

The authors have no conflicts of interest regarding this investigation.

REFERENCES:

1. Arruda VR, Siqueira LH, Gonçalves MS, Von Zuben PM, Soares MCP, Menezes R, Annichino-Bizzacchi JM, Costa FF. Prevalence of the mutation C677 → T in the methylene tetrahydrofolate reductase gene among distinct ethnic groups in Brazil. Am J Med Genet. 1998; 78:332–335; doi: 10.1002/(sici)1096-8628(19980724)78:4<332::aid-ajmg5>3.0.co;2-n

2. Graydon JS, Claudio K, Baker S, Kocherla M, Ferreira M, Roche-Lima A, Rodríguez-Maldonado J, Duconge J, Ruaño G. Ethnogeographic prevalence and implications of the 677C>T and 1298A>C MTHFR polymorphisms in US primary care populations. Biomark Med. 2019; 13:649–661; doi: 10.2217/bmm-2018-0392

3. Dean L. Methylenetetrahydrofolate Reductase Deficiency. Med. Genet. Summ. 2016; Bookshelf ID: NBK66131

4. Sandeep Goyal, V.K. Bansal, Dhruba Sankar Goswami, Suresh Kumar. sVascular Endothelial Dysfunction: Complication of Diabete Mellitus and Hyperhomocysteinemia. Research J. Pharm. and Tech. 2010; 3 (3): 657-664.

5. Izmirli M. A literature review of MTHFR (C677T and A1298C polymorphisms) and cancer risk. Mol Biol Reports. 2012; 40:625–637; doi: 10.1007/s11033-012-2101-2

6. Liew SC, Gupta E Das. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism: Epidemiology, metabolism and the associated diseases. Eur J Med Genet. 2015; 58:1–10; doi: 10.1016/j.ejmg.2014.10.004

7. Weisberg I, Tran P, Christensen B, Sibani S, Rozen R. A Second Genetic Polymorphism in Methylenetetrahydrofolate Reductase (MTHFR) Associated with Decreased Enzyme Activity. Mol Genet Metab. 1998; 64:169–172; doi: 10.1006/mgme.1998.2714

8. You W, Li Z, Jing C, Qian-Wei X, Yu-Ping Z, Weng-Guang L, Hua-Lei L. MTHFR C677T and A1298C Polymorphisms were associated with bladder cancer risk and disease progression: A meta-analysis. DNA Cell Biol. 2012; 32:260–267; doi: 10.1089/dna.2012.1931

9. Ferlazzo N, Currò M, Zinellu A, Caccamo D, Isola G, Ventura V, Carru C, Matarese G, Ientile R. Influence of MTHFR Genetic Background on p16 and MGMT Methylation in Oral Squamous Cell Cancer. Int J Mol Sci. 2017; doi: 10.3390/ijms18040724

10. Pande M, Chen J, Amos CI, Lynch PM, Broaddus R, Frazier ML. Influence of Methylenetetrahydrofolate Reductase Gene Polymorphisms C677T and A1298C on Age-Associated Risk for Colorectal Cancer in a Caucasian Lynch Syndrome Population. Cancer Epidemiol Biomarkers. 2017; 16:1753–1759; doi: 10.1158/1055-9965.EPI-07-0384

11. Eldeeb MK, Shoaib MMAE, Abd-Elmonem EA, Saeed HMS, Embaby AM, Farouk AM, Rashad RM. Genetic polymorphisms and gene expression of one-carbon metabolizing enzymes and their relation to breast cancer. Egypt J Med Hum Genet. 2022; 23:1–17; doi: https://doi.org/10.1186/s43042-022-00296-8

12. Petrone I, Bernardo PS, Santos EC Dos, Abdelhay E. MTHFR C677T and A1298C Polymorphisms in Breast Cancer, Gliomas and Gastric Cancer: A Review. Genes. 2021; 12: 587doi: 10.3390/genes12040587

13. V. Jayashree, Malarkodi Velraj. Breast Cancer and various Prognostic Biomarkers for the diagnosis of the disease: A Review. Research J. Pharm. and Tech. 2017; 10(9): 3211-3216. doi: 10.5958/0974-360X.2017.00570.4

14. Waill A. Elkhateeb, Mohamed A. Mohamed, Walid Fayad, Mahmoud Emam, Ibrahim M. Nafady, Ghoson M. Daba. Molecular Identification, Metabolites profiling, Anti-breast cancer, Anti-colorectal cancer, and antioxidant potentials of Streptomyces zaomyceticus AA1 isolated from a remote bat cave in Egypt. Research J. Pharm. and Tech. 2020; 13(7): 3072-3080. doi: 10.5958/0974-360X.2020.00545.4

15. Shiv Kumar Patel, Moumita Sinha, Mitashree Mitra. Glutathione-S-transferase M1 and T1 gene Polymorphism as Risk Factors of Oral Squamous Cell Carcinoma: A Preliminary Investigation. Research J. Pharm. and Tech. 2012; 5(7): 918-920.

16. F. Mariyam Niyas, Savitha G. Metabolic Antioxidant Status in Oral Squamous Cell Carcinoma. Research J. Pharm. and Tech. 2018; 11(10): 4362-4364. doi: 10.5958/0974-360X.2018.00798.9

17. Roushan Mubarak, Shaden Haddad, Outhman Hamdan. Frequency of CYP1A1*2A Polymorphism in Syrian Children with Acute Lymphoblastic Leukemia. Research J. Pharm. and Tech. 2016; 9(2): 135-138. doi: 10.5958/0974-360X.2016.00022.6

18. Zainab Mir1, Rosliza2, Behroz Naeem1, Ilyas Muhammad Nadeem2, Prof. Nordin Bin Simbak, Prof. Zubaidi ALA, Prof. Tengku Mohammad Ariff, Khalili MR, Mohammad Amjad Kamal, Atif Amin Baig. Synergistic Molecular Effect of BDNF, ApoE and MTHFR in inducing Depression in Alzheimer’s Disease. Research J. Pharm. and Tech. 2018; 11(10): 4317-4323. doi: 10.5958/0974-360X.2018.00790.4

19. Sriram S., Arul Amutha Elizabeth, Akila L. Cost Analysis of SGLT2 Inhibitors in patients with type 2 Diabetes in India. Research J. Pharm. and Tech. 2020; 13(12):5861-5865. doi: 10.5958/0974-360X.2020.01021.5

20. S. Preethikaa, M. P. Brundha. Awareness of Diabetes Mellitus among General Population. Research J. Pharm. and Tech. 2018; 11(5):1825-1829 doi: 10.5958/0974-360X.2018.00339.6

21. Vinod K Mathew, Kishore Gnana Sam, Beulah Samuel, Amit Kumar Das. Epidemiology of Schizophrenia in an Indian Hospital. Research J. Pharm. and Tech. 2020; 13(1):219-223. doi: 10.5958/0974-360X.2020.00044.X

22. Nursal AF, Kaya S, Sezer O, Karakus N, Yigit S. MTHFR gene C677T and A1298C variants are associated with FMF risk in a Turkish cohort. J Clin Lab Anal. 2018; doi: 10.1002/jcla.22259

23. Safarinejad MR, Shafiei N, Safarinejad S. Genetic susceptibility of methylenetetrahydrofolate reductase (MTHFR) gene C677T, A1298C, and G1793A polymorphisms with risk for bladder transitional cell carcinoma in men. Med Oncol. 2010; 281 28:398–412; doi: 10.1007/s12032-010-9723-9

24. Mutchinick OM, López MA, Luna L, et al. High Prevalence of the Thermolabile Methylenetetrahydrofolate Reductase Variant in Mexico: A Country with a Very High Prevalence of Neural Tube Defects. Mol Genet Metab. 1999; 68:461–467; doi: 10.1006/mgme.1999.2939

25. Lu Y, Zhao Y, Liu G, Wang X, Liu Z, Chen B, Hui R. Factor V gene G1691A mutation, prothrombin gene G20210A mutation, and MTHFR gene C677T mutation are not risk factors for pulmonary thromboembolism in Chinese population. Thromb Res. 2002; 106:7–12; doi: 10.1016/s0049-3848(02)00064-6

26. Gemmati D, Ongaro A, Scapoli GL, et al. Common Gene Polymorphisms in the Metabolic Folate and Methylation Pathway and the Risk of Acute Lymphoblastic Leukemia and non-Hodgkin’s Lymphoma in Adults. Cancer Epidemiol Biomarkers Prev. 2004; 13:787–794; PMID: 15159311

27. De Franchis R, Mancini FP, D’Angelo A, Sebastio G, Fermo I, De Stefano V, Margaglione M, Mazzola G, Di Minno G, Andria G. Elevated total plasma homocysteine and 677C-->T mutation of the 5,10-methylenetetrahydrofolate reductase gene in thrombotic vascular disease. Am J Hum Genet. 1996; 59:262; PMID: 8659535

28. Franco RF, Araújo AG, Guerreiro JF, Elion J, Zago MA. Analysis of the 677 C→T mutation of the methylenetetrahydrofolate reductase gene in different ethnic groups. Thromb Haemost. 1998; 79:119–121; PMID: 9459335

29. Nishio H, Lee MJ, Fujil M, Kario K, Kayaba K, Shimada K, Matsuo M, Sumino K. A common mutation in methylenetetrahydrofolate reductase gene among the Japanese population. Jpn J Hum Genet. 1996; 41:247–251; doi: 10.1007/BF01875985

30. Antoniadi T, Hatzis T, Kroupis C, Economou-Petersen E, Petersen MB. Prevalence of Factor V Leiden, Prothrombin G20210A, and MTHFR C677T Mutations in a Greek Population of Blood Donors. J Hematol. 1999; 61:265–267; doi: 10.1002/(sici)1096-8652(199908)61:4<265::aid-ajh8>3.0.co;2-#

31. Sazci A, Ergul E, Kaya G, Kara I. Genotype and allele frequencies of the polymorphic methylenetetrahydrofolate reductase gene in Turkey. Cell Biochem Funct. 2005; 23:51–54; doi: 10.1002/cbf.1132

32. Koch MC, Stegmann K, Ziegler A, Schröter B, Ermert A. Evaluation of the MTHFR C677T allele and the MTHFR gene locus in a German spina bifida population. Eur J Pediatr. 1998; 1576 157:487–492; doi: 10.1007/s004310050860

33. Skibola CF, Smith MT, Kane E, Roman E, Rollinson S, Cartwright RA, Morgan G. Polymorphisms in the methylenetetrahydrofolate reductase gene are associated with susceptibility to acute leukemia in adults. Proc Natl Acad Sci U S A. 1999; 96:12810; doi: 10.1073/pnas.96.22.12810

34. Van Der Put NMJ, Gabreëls F, Stevens EMB, Smeitink JAM, Trijbels FJM, Eskes TKAB, Van Den Heuvel LP, Blom HJ. A second common mutation in the methylenetetrahydrofolate reductase gene: an additional risk factor for neural-tube defects? Am J Hum Genet. 1998; 62:1044; doi: 10.1086/301825

35. Al-Habboubi H, Tamim H, Ameen G, Almawi WY. A common mutation in 5,10-methylenetetrahydrofolate reductase (MTHFR) gene in two Arab communities. J Thromb Haemost. 2003; 1:2246–2248; doi: 10.1046/j.1538-7836.2003.00390.x

36. Thomas F, Motsinger-Reif AA, Hoskins JM, Dvorak A, Roy S, Alyasiri A, Myerson RJ, Fleshman JW, Tan BR, McLeod HL. Methylenetetrahydrofolate reductase genetic polymorphisms and toxicity to 5-FU-based chemoradiation in rectal cancer. Br J Cancer. 2011; 10511 105:1654–1662; doi: 10.1038/bjc.2011.442

37. Sabbagh AS, Mahfoud Z, Taher A, Zaatari G, Daher R, Mahfouz RAR. High prevalence of MTHFR gene A1298C polymorphism in Lebanon. Genet Test. 2008; 12:75–80; doi: 10.1089/gte.2007.0064

38. Eid SS, Rihani G. Prevalence of Factor V Leiden, Prothrombin G20210A, and MTHFR C677T Mutations in 200 Healthy Jordanians. Am Soc Clin Lab Sci. 2004; 17:200–202; PMID: 15559724

39. Stevenson RE, Schwartz CE, Du YZ, Adams J. Differences in methylenetetrahydrofolate reductase genotype frequencies, between Whites and Blacks. Am J Hum Genet. 1997 60:229; PMID: 8981967

40. Angeline T, Jeyaraj N, Granito S, Tsongalis GJ (2004) Prevalence of MTHFR gene polymorphisms (C677T and A1298C) among Tamilians. Exp Mol Pathol. 2004; 77:85–88; doi: 10.1016/j.yexmp.2004.04.006

41. Gibson CS, MacLennan AH, Rudzki Z, et al. (2005) The prevalence of inherited thrombophilias in a Caucasian Australian population. Pathology. 2005; 37:160–163; doi: 10.1080/00313020500058250

42. Almawi WY, Finan RR, Tamim H, Daccache JL, Irani-Hakime N. (2004) Differences in the Frequency of the C677T Mutation in the Methylenetetrahydrofolate Reductase (MTHFR) Gene Among the Lebanese Population. Am J Hematol. 2004; 76:85–87; doi: 10.1002/ajh.20047

43. Kahleová R, Palyzová D, Zvára K, Zvárová J, Hrach K, Nováková I, Hyánek J, Bendlová I, Ko ich V. (2002) Essential hypertension in adolescents: Association with insulin resistance and with metabolism of homocysteine and vitamins. Am J Hypertens. 2002; 15:857–864; doi: 10.1016/s0895-7061(02)02984-9

44. Falchi A, Giovannoni L, Piras IS, Calo CM, Moral P, Vona G, Varesi L. (2005) Prevalence of genetic risk factors for coronary artery disease in Corsica island (France). Exp Mol Pathol. 2005; 79:210–213; doi: 10.1016/j.yexmp.2005.09.005

45. Zetterberg H, Coppola A, D’Angelo A, Palmér M, Rymo L, Blennow K. No association between the MTHFR A1298C and transcobalamin C776G genetic polymorphisms and hyperhomocysteinemia in thrombotic disease. Thromb Res. 2002; 108:127–131; doi: 10.1016/s0049-3848(03)00004-5

46. Esfahani ST, Cogger EA, Caudill MA. (2003) Heterogeneity in the prevalence of methylenetetrahydrofolate reductase gene polymorphisms in women of different ethnic groups. J Am Diet Assoc. 2003; 103:200–207; doi: 10.1053/jada.2003.50030

47. Pereira TV, Rudnicki M, Pereira AC, Pombo-De-Oliveira MS, Franco RF. 5,10-Methylenetetrahydrofolate Reductase Polymorphisms and Acute Lymphoblastic Leukemia Risk: A Meta-analysis. Cancer Epidemiol Biomarkers Prev. 2006; 15:1956–63; doi: 10.1158/1055-9965.EPI-06-0334

48. Kiffmeyer WR, Langer E, Davies SM, Envall J, Robison LL, Ross JA. Genetic polymorphisms in the Hmong population. Cancer. 2004; 100:411–417; doi: 10.1002/cncr.11913

49. De Marco P, Calevo MG, Moroni A, Arata L, Merello E, Finnell RH, Zhu H, Andreussi L, Cama A, Capra V. Study of MTHFR and MS polymorphisms as risk factors for NTD in the Italian population. J Hum Genet. 2002; 47:319–324; doi: 10.1007/s100380200043

50. Peng F, Labelle LA, Rainey BJ, Tsongalis GJ. Single nucleotide polymorphisms in the methylenetetrahydrofolate reductase gene are common in US Caucasian and Hispanic American populations. Int J Mol Med. 2001; 8:509–511; doi: 10.3892/ijmm.8.5.509

51. Perez ABA, D’Almeida V, Vergani N, Oliveira AC de, Lima FT de, Brunoni D. Methylenetetrahydrofolate reductase (MTHFR): incidence of mutations C677T and A1298C in Brazilian population and its correlation with plasma homocysteine levels in spina bifida. Am J Med Genet Part A. 2003; 119A:20–25; doi: 10.1002/ajmg.a.10059

52. Shrubsole MJ, Gao YT, Cai Q, Shu XO, Dai Q, Hébert JR, Jin F, Zheng W. MTHFR Polymorphisms, Dietary Folate Intake, and Breast Cancer RiskResults from the Shanghai Breast Cancer Study. Cancer Epidemiol Biomarkers Prev. 2004; 13:190–196; doi: 10.1158/1055-9965.epi-03-0273

53. Hiraoka M, Kato K, Saito Y, Yasuda K, Kagawa Y. Gene–nutrient and gene–gene interactions of controlled folate intake by Japanese women. Biochem Biophys Res Commun. 2004; 316:1210–1216; doi: 10.1016/j.bbrc.2004.02.174

54. Markan S, Sachdeva M, Sehrawat BS, Kumari S, Jain S, Khullar M. MTHFR 677 CT/MTHFR 1298 CC genotypes are associated with increased risk of hypertension in Indians. Mol Cell Biochem. 2007; 3021 302:125–131; doi: 10.1007/s11010-007-9434-5

55. Lievers KJ, Boers GH, Verhoef P, Heijer M, Kluijtmans LA, Put NM, Trijbels FJ, Blom HJ. A second common variant in the methylenetetrahydrofolate reductase (MTHFR) gene and its relationship to MTHFR enzyme activity, homocysteine, and cardiovascular disease risk. J Mol Med. 2001; 799 79:522–528; doi: 10.1007/s001090100253

56. Isotalo PA, Wells GA, Donnelly JG. Neonatal and Fetal Methylenetetrahydrofolate Reductase Genetic Polymorphisms: An Examination of C677T and A1298C Mutations. Am J Hum Genet. 2000; 67:986; doi: 10.1086/303082

Received on 30.11.2022 Modified on 22.12.2022

Research J. Pharm. and Tech 2023; 16(9):4365-4369.

DOI: 10.52711/0974-360X.2023.00714