Homocystinuria due to MTHFR deficiency
- 5,10 alpha methylenetetrahydro-folate reductase deficiency
- 5,10-alpha-methylenetetrahydro-folate reductase deficiency
- Homocysteinemia due to methylenetetrahydro-folate reductase deficiency
- Homocysteinuria due to methylenetetrahydro-folate reductase deficiency
- Homocystinuria due to methylene tetrahydrofolate reductase deficiency
Your QuestionI have MTHFR deficiency. Can you tell me more about this in lay language?
We have identified the following information that we hope you find helpful. If you still have questions, please contact us.
Questions on this page
- What is homocysteinemia due to MTHFR deficiency?
- What are the signs and symptoms of homocysteinemia due to MTHFR deficiency?
- What causes homocysteinemia due to MTHFR deficiency?
- How is homocysteinemia due to MTHFR deficiency inherited?
- Is genetic testing available for homocysteinemia due to MTHFR deficiency?
- How might homocysteinemia due to MTHFR deficiency be treated?
- How can I find a genetics professional in my area?
For more information on common MTHFR gene mutations (such as C677T) visit our page: MTHFR gene mutation
A few cases of severe homocysteinemia have been due to rare MTHFR gene mutations (sometimes in combination with a second common MTHFR gene mutation). Symptoms in these patients varied greatly but often involved pronounced neurological symptoms and blood vessel disease. The age of the patients when they first experienced symptoms varied from infancy to adulthood.
Common MTHFR gene mutations cause less severe, although still significantly raised levels of homocysteine. The most well studied MTHFR mutation, is C677T. An estimated 11% of Americans carry two copies of this mutation. People with two copies of C677T have higher homocysteine levels than those without the mutation (people with one copy of C677T have mildly raised homocysteine levels).
Many studies have investigated the health effects of high homocysteine levels and/or having two C677T MTHFR gene mutations. Studies suggest that an elevated level of homocysteine in the blood is associated with an increased risk for heart disease, including coronary heart disease and stroke.
Weaker associations have been suggested between high homocysteine levels and narrowing of the carotid arteries (the arteries on each side of your neck), blood clots in deep veins (often in the lower leg and thigh), a sudden blockage in a lung artery, and pregnancy complications (such as preeclampsia, placental abruption, fetal growth restriction, stillbirth, and neural tube defects).
Studies involving MTHFR and homocysteine and the following conditions have been completed, but with conflicting and varied results:
Recurrent pregnancy loss
Cerebral venous thrombosis
Acute lymphoblastic leukemia
There are many different gene mutations that can occur in the MTHFR gene that can result in a MTHFR enzyme that is not working as it should. The most common MTHFR gene mutation is the C677T mutation.
Please note: Most of the laboratories listed through GeneTests do not accept direct contact from patients and their families; therefore, if you are interested in learning more, you will need to work with a health care provider or a genetics professional.
Genetics clinics are a source of information for individuals and families regarding genetic conditions, treatment, inheritance, and genetic risks to other family members. More information about genetic consultations is available from Genetics Home Reference. To find a genetics clinic, we recommend that you contact your primary healthcare provider for a referral.
The following online resources can help you find a genetics professional in your community:
- The National Society for Genetic Counselors provides a searchable directory of US and international genetic counseling services.
- The American College of Medical Genetics has a searchable database of US genetics clinics.
- The University of Kansas Medical Center provides a list of US and international genetic centers, clinics, and departments.
- The American Society of Human Genetics maintains a database of its members, which includes individuals who live outside of the United States. Visit the link to obtain a list of the geneticists in your country, some of whom may be researchers that do not provide medical care.
- Homocystinuria. Genetics Home Reference (GHR). 2008; http://www.ghr.nlm.nih.gov/condition=homocystinuria. Accessed 3/16/2011.
- Homocystinuria due to deficiency of N(5,10)-Methylenetetrahydrofoloate reductase activity. Online Mendelian Inheritance in Man. 2007; http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=236250. Accessed 5/13/2009.
- Homocysteine. American Academy of Family Physicians. 2006; http://familydoctor.org/online/famdocen/home/articles/249.html. Accessed 5/13/2009.
- Rosenson RS, Kang DS. Overview of homocysteine. In: Fletcher RH, Freeman MW. UpToDate. Waltham, MA: UpToDate; 2015; Accessed 3/27/2015.
- MTHFR. Genetics Home Reference (GHR). Februrary 2011; http://ghr.nlm.nih.gov/gene/MTHFR. Accessed 7/14/2011.
- Liew SC, Gupta ED. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism: epidemiology, metabolism and the associated diseases. Eur J Med Genet. 2015 Jan; 58(1):1-10. Accessed 3/27/2015.
- Goodnight SH and Griffin JH. Hereditary Thrombophilia. In: Ernest Beutler, Marshall A. Lichtman, Barry S. Coller, Thomas J. Kipps, and Uri Seligsohn. Williams Hematology, 6th ed. Philadelphia, PA: McGraw-Hill ; 2001;
- Homocystinuria due to deficiency of N(5,10)-Metylenetetrahydrofolate Reductase Activity. Online Medelian Inheritance of Man (OMIM). June 2007; http://www.omim.org/entry/236250. Accessed 7/11/2011.