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Diseases

Genetic and Rare Diseases Information Center (GARD)

Homocystinuria due to MTHFR deficiency


Other Names for this Disease
  • Homocysteinemia due to methylenetetrahydro-folate reductase deficiency
  • Methylenetetrahydro-folate reductase deficiency
  • Homocysteinuria due to methylenetetrahydro-folate reductase deficiency
  • 5,10-alpha-methylenetetrahydro-folate reductase deficiency
  • 5,10 alpha methylenetetrahydro-folate reductase deficiency
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Your Question

I have MTHFR deficiency. Can you tell me more about this in lay language?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is homocystinuria due to MTHFR deficiency?

Homocystinuria due to MTHFR deficiency refers to a metabolic condition caused by rare MTHFR gene mutations that result in severe homocystinuria, abnormal clotting, developmental delay, seizures, intellectual disability, and microcephaly.[1] It is inherited in an autosomal recessive fashion.

For more information on common MTHFR gene mutations (such as C677T) visit our page: MTHFR gene mutation
Last updated: 3/17/2016

What are the signs and symptoms of homocysteinemia due to MTHFR deficiency?

This severe homocystinuria is caused by rare MTHFR gene mutations (sometimes in combination with a second common MTHFR gene mutation). In severe MTHFR deficiency, signs and symptoms become apparent in infancy, however the condition can be milder, presenting in later childhood or adulthood. Signs and symptoms may include global developmental delays (46% of cases), low muscle tone (35%), seizures (33%), failure to thrive (17%), blood vessel disease (16%) (blood clots), small head size (15%), ataxia (9%), and peripheral neuropathy (7%). Other possible symptoms include bone disease (scoliosis), and mental health and behavior problems (e.g., attention deficit disorder and hyperactivity). Life expectancy will vary depending on the severity of the deficiency.[2]

For information on signs and symptoms reported in association with common MTHFR gene mutations, such as C677T, please visit our MTHFR Gene Mutation resource page.
Last updated: 4/14/2015

What causes homocystinuria due to MTHFR deficiency?

Homocystinuria due to MTHFR deficiency is caused by mutations in the MTHFR gene. This gene tells the body how to make an enzyme, also called MTHFR. MTHFR is important for a chemical reaction in the body involving forms of the vitamin folate. Mutations in the MTHFR gene result in an enzyme that doesn't work like it should, causing a buildup of homocysteine in the body.[3]
Last updated: 4/14/2015

How is homocystinuria due to MTHFR deficiency inherited?

Homocystinuria due to MTHFR deficiency is inherited in an autosomal recessive fashion, which means that both copies of the gene in each cell have mutations in the MTHFR gene.[1]

For more information on the inheritance of common MTHFR gene mutations (such as C677T) visit our page: MTHFR gene mutation
Last updated: 4/14/2015

How can I find a genetics professional in my area?

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:
Last updated: 5/18/2016

References
Other Names for this Disease
  • Homocysteinemia due to methylenetetrahydro-folate reductase deficiency
  • Methylenetetrahydro-folate reductase deficiency
  • Homocysteinuria due to methylenetetrahydro-folate reductase deficiency
  • 5,10-alpha-methylenetetrahydro-folate reductase deficiency
  • 5,10 alpha methylenetetrahydro-folate reductase deficiency
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.