Homocystinuria caused by MTHFR deficiency

Homocystinuria caused by 5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency occurs when the body makes too little MTHFR enzyme or none at all, or it makes MTHFR enzyme that does not work properly. Enzymes are proteins that regulate the body’s tissues and organs. Specifically, MTHFR helps convert an important amino acid—homocysteine— back to methionine, another important amino acid.

When this process does not occur as it should, blood levels of homocysteine increase and blood levels of methionine decrease. This causes harmful symptoms to develop.

What are the signs and symptoms of homocystinuria caused by MTHFR deficiency?

Symptoms of homocystinuria caused by severe MTHFR deficiency can begin in infancy or early childhood. Symptoms may include:

Behavioral or mental health problems
Developmental delay or disability, such as being slow to roll over, sit up, walk or talk
Movement or muscle problems
Seizures
Learning or memory problems
Trouble breathing
Lack of ability to stay awake, aware, or oriented to place and time

Early detection and treatment are critical to help reduce serious health problems.

How is homocystinuria caused by MTHFR deficiency diagnosed?

Newborn screening for homocystinuria caused by MTHFR deficiency is not available in any state at this time. If your child has symptoms that could be signs of homocystinuria caused by MTHFR deficiency, your doctor will order lab tests. The following results may point to a positive diagnosis:

• High levels of homocysteine in blood and urine
• Low levels of methionine in blood and urine
• Reduced activity of the MTHFR enzyme

Genetic testing can confirm the diagnosis.

Medical geneticists are doctors who specialize in diagnosing and treating people with MTHFR deficiency.

How is homocystinuria caused by MTHFR deficiency treated?

The overall goal of treatment is to lessen symptoms by reducing the level of homocysteine and maintaining a normal level of methionine in the blood. Treatment may include:

  • Taking CYSTADANE® (betaine anhydrous for oral solution)

  • Taking other therapies as directed by your doctor

Always check with your doctor about what therapies are right for you.

INDICATIONS AND USAGE

CYSTADANE (betaine anhydrous for oral solution) is indicated in children and adults for the treatment of homocystinuria to decrease high homocysteine blood levels. Homocystinuria is a rare genetic disorder in which there is an abnormal accumulation of the amino acid homocysteine in the blood and urine. The following are considered to be homocystinuria disorders:

  • Cystathionine beta-synthase (CBS) deficiency
  • 5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency
  • Cobalamin cofactor metabolism (cbl) defect

IMPORTANT SAFETY INFORMATION

  • Hypermethioninemia in Patients with CBS Deficiency: CYSTADANE may worsen high methionine blood levels and accumulation of excess fluid in the brain has been reported. If you have been told you have CBS deficiency, your doctor will be monitoring your methionine blood levels to see if changes in your diet and dosage are necessary.
  • Most common side effects were nausea and gastrointestinal distress, based on a survey of doctors.
  • To report SUSPECTED SIDE EFFECTS, contact Recordati Rare Diseases Inc. at 1-888-575-8344, or FDA at 1‑800-FDA-1088 or www.fda.gov/medwatch.
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IMPORTANT SAFETY INFORMATION

  • Hypermethioninemia in Patients with CBS Deficiency: CYSTADANE may worsen high methionine blood levels and accumulation of excess fluid in the brain has been reported. If you have been told you have CBS deficiency, your doctor will be monitoring your methionine blood levels to see if changes in your diet and dosage are necessary.
  • Most common side effects were nausea and gastrointestinal distress, based on a survey of doctors.