Molecular biology of methylenetetrahydrofolate reductase. Methylenetetrahydrofolate reductase mthfr is a key enzyme for the critical process of onecarbon metabolism involving folate and homocysteine metabolisms. Mthfr mutation may increase the risk of cardiovascular disease and vitamin b deficiencies those with an mthfr mutation are at risk for poor mthfr enzyme efficiency. The methylenetetrahydrofolate reductase mthfr c677t polymorphism is associated with various diseases vascular, cancers, neurology, diabetes, psoriasis, etc with the epidemiology of the polymorphism of the c677t that varies dependent on the geography and ethnicity. Cellular and mitochondrial glutathione redox imbalance in lymphoblastoid cells derived from children with autism. Several studies have examined the association between the mthfr c677t polymorphism and mtx toxicity and efficacy in ra, but their conclusions remain controversial. Investigation of mthfr gene c677t polymorphism in cardiac. Jan, 2016 there are over fifty types of mthfr gene mutations. The most common variant in the mthfr gene is mthfr c677t. Mthfr gene, folic acid, and preventing neural tube defects. The mthfr c677t polymorphism contributes to increased risk of. Aug 07, 2017 mthfr polymorphisms are also strongly linked to autoimmune disease, specifically type 1 diabetes, hashimotos thyroiditis, graves disease, rheumatoid arthritis, vitiligo, and multiple sclerosis. With the identification of additional patients with severe mthfr deficiency, the heterogeneity of this disorder became manifest.
Mthfr c677t is a common gene polymorphism that has been shown to be associated with hyperhomocysteinemia. Methylenetetrahydrofolate reductase mthfr c677t polymorphism. The results showed that mthfr c677t polymorphism may be a risk factor for ad in asians, apoe. Folate, vitamin b12, homocysteine, and the mthfr 677ct polymorphism in anxiety and depressionthe hordaland homocysteine study. When methylfolate levels are low, so are neurotransmitters. The link between mthfr gene mutations and disease, including. Mthfr, cancer, c677t, a1298c, and polymorphisms were key words used to focus the search. Mthfr polymorphisms affect the metabolism of folate and may predispose these individuals to a variety of nutrient deficiencies. Cancer neural tube defects male infertility miscarriages diabetic nephropathy stroke schizophrenia, anxiety, depression, dementia selhub j. Association of mthfr a1298c polymorphism with conotruncal. Oct 21, 20 the 1298ac polymorphism in methylenetetrahydrofolate reductase mthfr. Sixtyeight patients with ra were included in the study.
Learn about determining your mthfr status and getting treatment. It is the gene responsible for facilitating methylation, repairing dna, protein formation, homocysteine conversion, folate processing, and toxin detoxification. When we identify a part of the sequence that varies, we call it a variant. The methylenetetrahydrofolate reductase mthfr gene 677c t polymorphism was reported to be related to an elevated level of homocysteine hcy which is an independent factor for coronary heart disease and stroke. Learn how most of the us population carries the gene for this mysterious disorder mthfr and up to 15% actually have the disease they have methylation problems, folate deficiency, and lack of methylfolate in their diet and its killing them, and possibly.
People who inherit two copies of c677t have a higher risk for having a child with a neural tube defect. Molecular biology of methylenetetrahydrofolate reductase mthfr and overview of mutationspolymorphisms daniel leclerc, sahar sibani and rima rozen assays for methylenetetrahydrofolate reductase polymorphisms arve ulvik and per magne ueland biochemical characterization of. Disease associations with the mthfr a1298c polymorphism associated with the following disease states. Theres a decent chance you or someone in your family has the mthfr gene variant.
Mthfr c677t and a1298c polymorphisms were associated with bladder cancer risk and disease progression. Higher incidence of c677t polymorphism of the mthfr gene in north indian patients with vascular disease. The 677ct polymorphism of mthfr was investigated in the analysis of ioannidis et al. Methylenetetrahydrofolate reductase mthfr atp science. Methylene tetrahydrofolate reductase mthfr is an important enzyme in the mtx pathway and is involved in folate metabolism and dna synthesis. Polymorphisms in the mthfr gene can alter or decrease the activity of methylenetetrahydrofolate reductase, leading to a mild increase of homocysteine in the blood hyperhomocysteinemia. The association of the mthfr c677t polymorphism with. In particular, the c677t polymorphism shows a wide regional and ethnic variation. Mthfr is a gene that makes an enzyme called m ethylene t etra h ydro f olate r eductase. Since then, more than 5,000 studies have tried to link mthfr variants to a terrifying grab bag of more than 400 health problems. The aim of the present study was to assess the risk of mthfr c677t polymorphism for ad. If you have a mthfr gene polymorphism you may not be able to convert folic acid and other inactive forms of folate into the active form that our body needs. The mthfr c677t polymorphism causes thermolability and reduced mthfr activity, leading to lower levels of 5methyltetrahydrofolate, an accumulation of 5,10methylene thg, increased plasma homocysteine levels and change in the cellular composition. Basic information about the mthfr gene most mthfr testing is unnecessary.
Having two c677t variants and elevated homocysteine levels may cause a slightly higher risk for blood clots. Mthfr c677t and a1298c polymorphisms may contribute to the risk of parkinsons disease. Research indicates that individuals who have the 677ct polymorphism on both copies of the mthfr gene have an increased risk of developing vascular disease, including heart disease and stroke. Mthfr gene c677t polymorphism in autism spectrum disorders. In other words, the likelihood of having one or both of the mthfr polymorphisms, as well as the frequency of variants alleles of the mthfr gene, were not found to be more prevalent in those with autoimmune thyroid disease compared to those who do not. Pdf preface of book mthfr polymorphisms and disease. Methylenetetrahydrofolate reductase catalyzes the conversion of 5,10methylenetetrahydrofolate to 5methyltetrahydrofolate, a cosubstrate for homocysteine remethylation to methionine. Mthfr is a key gene in regulating the bodys folate metabolism and, consequently, is involved in the methylation cycle. The association between methylenetetrahydrofolate reductase mthfr c677t polymorphism and susceptibility to alzheimers disease ad was examined in previous studies. Mthfr polymorphisms, and thus lowered lmethylfolate levels is associated with symptoms and conditions such as mental health disorders, cardiovascular disease, obesity and birth defects.
Mthfr enzyme is responsible for converting 5,10 methylenetetrahydrofolate to 5methyltetrahydrofolate. Mthfr tells our body how to create an enzyme involved in breaking down the amino acid homocysteine. Up to 50% of people carry a genetic variation or snp pronounced snip of the mthfr gene. Mthfr gene variant genetic and rare diseases information.
For the 677t polymorphism, homozygote variants have 30% enzyme activity in comparison with homozygotes for the wildtype 677c allele, while heterozygotes retain 65% wildtype mthfr enzyme activity 8, 16. Our 4 week old daughter was diagnosed en utero with a congenital heart defect and then 22q after amniocentesis. Other papers discuss the relationship of mthfr polymorphisms to arterial occlusive disease, venous thrombosis, neural tube defects, pregnancy complications, neuropsychiatric disease, renal failure, colorectal neoplasia, and pharmacogenetics. The 677ct polymorphism has also been suggested as a risk factor for cleft lip and palate, a birth defect in which there is a split in the upper lip and. A primer on methylation beyond mthfr optimizing genes.
Currently, there are 7215 research articles on mthfr as of june 25, 2019. She had heart surgery on day 2, and were still in the hospital working on getting home. The two mthfr gene polymorphisms that are the most common and the most frequently studied are 677ct and a change that replaces the nucleotide adenosine with the nucleotide cytosine at position 1298 written. They found that the frequencies of the genetic marker of interest in control populations often 58% showed large. As a major gene associated with homocysteine levels and various thromboses, it is the gene. The mutation of the mthfr gene is a single nucleotide polymorphism that causes an alaninetovaline amino acid substitution 8,15. Case control association studies on mthfr c677t polymorphism and alzheimers disease ad have been repeatedly performed over the last two decades, but the results are inconclusive. The mthfr c677t polymorphism was significantly associated with 42 clinical disorders p, mostly relating to the diseases of circulatory system, birth defects, and cancers. This book covers many of the complex traits that have been reported to be influenced by the wellcharacterized 677ct variant. To investigate the relationships of polymorphisms in genes whose protein products are related in the metabolic pathway of folic acid, particularly mtrr a66g, rfc1 g80a, and mthfr c677t and a1298c, and disease activity in mexican patients with rheumatoid arthritis ra treated with methotrexate mtx. Thats an increase of 2,637 papers in 7 years at a rate of 376 new papers published a year. Jun 18, 2012 in particular, the c677t polymorphism shows a wide regional and ethnic variation. Consequently, folate and folic acid cannot be efficiently converted into their active form, known as 5mthf or lmethylfolate. Mutation, polymorphism, variant and sequence changethese terms are used interchangeably throughout the book to denote.
Ben lynch, anaturopathic physician who has focused attention on mthfr polymorphisms and genetic changes, and the linkage to diseases and conditions. If you have an mthfr polymorphism, enzymatic reactions can slow down by 4070%, leading to elevated homocysteine levels. Mthfr which is the abbreviation for the gene called methylenetetrahydrofolate reductase, i turned to dr. However, having a common variant in the mthfr gene does not change your medical care. Mthfr c677t polymorphism rs18013 was examined by polymerase chain reaction pcrrestriction fragment length polymorphism rflp. Studies on the role of mthfr in inflammatory bowel diseases ibd have yielded conflicting results, perhaps due in part to genetic heterogeneity. Mthfr is the gene responsible for production of the mthfr enzyme, which is the ratelimiting enzyme in folate cycle. Methylenetetrahydrofolate reductase mthfr in health and. The mthfr gene produces an enzyme called methylenetetrahydrofolate reductase. Jan 27, 2012 mthfr research is growing at an exponential rate. The c677t methylenetetrahydrofolate reductase mthfr polymorphism affects the distribution between folate species used for dna and rna syntheses and the 5methyltetrahydrofolate form required for homocysteine remethylation and thereby protein synthesis. Sep 27, 2017 methylenetetrahydrofolate reductase mthfr c677t polymorphism. The 677t variant of the methylenetetrahydrofolate reductase gene mthfr has been identified as a risk factor for vascular disease.
Some mutations of the mthfr gene may be associated with health problems and complications in pregnancy. Nonetheless, the mthfr gene variation does appear more commonly in those with hypothyroidism. I have a list of resources on the mthfr page that you might find helpful. Disease associations with the mthfr c677t polymorphism associated with the following disease states. There are two primary mthfr mutations, which can be thought of as irregular or incomplete versions of this gene, which later affects the mthfr enzyme introduced above.
There are over fifty types of mthfr gene mutations. Nov 30, 2018 the mthfr a1298c polymorphism reduces mthfr enzyme activity to a lesser extent than the mthfr c677t polymorphism. Blom neuropsychiatric disease and methylenetetrahydrofolate reductase b. Methylenetetrahydrofolate reductase mthfr is a critical enzyme in both folate and homocysteine metabolism. It lists the main functional polymorphisms of the mthfr gene to be c677t, a1298c, with other reported polymorphisms known for genes t1059c, t17c and g1793a. Im currently writing a book on the most effective naturopathic treatments for mental health disorders such as anxiety and depression and will be including a chapter on mthfr in this book. Due to various complications, she just started getting breast milk. Because each person has two copies of the mthfr gene, people can inherit one copy of a mthfr gene variant or two copies of it one from each parent. Mthfr gene polymorphism positive treatmentresistant. Mthfr polymorphisms our genes have a significant influence over our health and they may have variations, called single nucleotide polymorphisms snps, affecting the way we process nutrients or our dietary requirements. Neural tube defects, other congenital malformations and single nucleotide polymorphisms in the 5,10 methylenetetrahydrofolate reductase mthfr gene.
Mthfr normally plays a critical role in many important processes throughout the body. A gene variant is a change in a dna sequence that is different from the expected dna sequence. You may have an increased risk of heart disease, general inflammation, difficult pregnancies and a diminished ability to eliminate toxins including alcohol. The link between mthfr gene mutations and disease, including thyroid health an interview with dr. Of particular relevance to the comments below was the report of a heatsensitive mthfr in some homocystinuric patients, which was assumed to be caused by a deleterious mutation. The issue of a gene called mthfr and its link to disease includingthyroid disease is becoming an. Mthfr helps converts folate into the active form methyfolate that the body can use. Our results suggest that mthfr 1298c allele is a risk factor for conotruncal heart disease. Mthfr gene polymorphism, homocysteine and cardiovascular disease claudio cortese1 and corradino motti2 1department of internal medicine, university of tor vergata, via di tor vergata 5, 003 rome, italy. Metabolism, genes, polymorphisms and the associated. Mthfr polymorphisms and cardiovascular disease mthfrsupport. However, the two that are most commonly studied and tested for are c677t and a1298c. Methylenetetrahydrofolate reductase and psychiatric diseases. Mthfr gene polymorphism, homocysteine and cardiovascular disease.
The mthfr gene is on the short arm of chromosome 1 at location 36. Mthfr polymorphisms and disease by per magne ueland. Genetic testing can ascertain whether an individual has one of the common polymorphisms which leads to methylfolate deficiency, and can verify when. Ben lynch, expert on mthfr polymorphisms by mary shomon updated june, 2014. One mutation is known as the c677t polymorphism and is far more prevalent in. I was just diagnosed and had no idea what i was dealing with or where to find information. Nov 06, 2014 c677t polymorphism in the mthfr gene a222v, rs18013 is associated with a decrease in enzymatic activity to 3570% in homozygotes. Natural variation in this gene is common in otherwise healthy people. Methylenetetrahydrofolate reductase mthfr is key enzyme of folatehomocysteine pathway. The association between the c677t polymorphism in mthfr gene and the risk of thyroid cancer. Cardiovascular disease renal failure congenital abnormalities and pregnancy outcome cancer psychiatric disorders, schizophrenia, dementia, depression ibd autism downs syndrome.
Despite the high prevalence of methylene tetrahydrofolate reductase mthfr polymorphisms in numerous neuropsychiatric and. Abstract studies of genetic polymorphisms associated with the diseases of opiate dependency and abuse have focused primarily on genes related to dopamine and opioid receptors, neurotrophic factors, or the catecholomethyltransferase comt gene 1,2. Abstract the association between methylenetetrahydrofolate reductase mthfr gene c677t polymorphism and alzheimers disease ad risk has been widely reported with inconsistent results. This means at the 677 position in the mthfr gene, c is the expected dna base and t is the gene variant. Mthfr gene mutations are linked to many diseases to varying degrees, including heart disease, birth defects, alzheimers, cancer, and hypothyroidism. Mthfr 101 is a guide designed to remove the frustrating research and confusion that comes with this genetic variation.
Associations of the mthfr rs18013 polymorphism with coronary artery disease and lipid levels. To date, there have been some casecontrol studies of mthfr functional polymorphisms in autism and asd 14, 15, 17. The link between mthfr polymorphisms and cardiovascular disease has been known for some time, however recent research confirms increased risk of depression, bipolar and schizophrenia. Mthfr c677t and a1298c are the two main polymorphisms that you will read about online and in research studies.
The authors of this book examine the importance of mthfr in health and disease, including the folate requirements in healthy young women and its potential health implications and the role folate deficiency and mthfr polymorphisms may play in the complex mechanism of global dna hypomethylation. Genotype distributions of the mthfr c677t and nnmt rs694539 polymorphisms were similar in the two groups when evaluated separately and also according to the dominant genetic model p0. Many people have one or two genetic variants in the mthfr gene. I am looking forward to sharing my knowledge that will be based on many years of clinical experience and years of research in this field of health. Methylene tetrahydrofolate reductase mthfr is the ratelimiting enzyme in the methyl cycle, and it is encoded by the mthfr gene. Pcr fragments were amplified from 20 ng of each dna sample in 50. Mthfr polymorphisms and disease by ueland, per magne ebook. Bhargava s, ali a, parakh r, saxena r, srivastava lm. Subgroup and sensitivity analysis results showed that this polymorphism is a risk factor for down syndrome pregnancy in asian populations but not in caucasian population as well as in overall metaanalysis. Most of these studies have been performed in countries in which subjects are predominantly of white european descent. A recent, huge metaanalysis was designed to investigate the association of mthfr c677t polymorphism with ad.
A modest positive association has been found between the mthfr thermolabile polymorphism and many different medical complications, including, but not limited to, thromboembolic disease in. A maternal mthfr a1298c polymorphism is associated with down syndrome pregnancy. In regards to the c677t mutation, the heterozygous c677t mutation functions at 65% activity, with. Ben lynch, expert on mthfr gene mutations and polymorphisms.
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