Methylmalonyl-CoA mutase deficiency

Methylmalonyl-CoA mutase deficiency is a rare genetic disorder that affects the body's ability to metabolize certain proteins and fats. This condition is also known as Methylmalonic Acidemia or MMA for short. It is an inborn error of metabolism that can lead to a variety of health problems, including developmental delay, failure to thrive, and life-threatening metabolic crises.

Causes

Methylmalonyl-CoA mutase deficiency is caused by mutations in the MUT gene. This gene provides instructions for making an enzyme called methylmalonyl-CoA mutase. This enzyme is involved in the breakdown of certain amino acids and lipids. Mutations in the MUT gene reduce or eliminate the activity of this enzyme, which disrupts the normal breakdown of these substances and leads to a buildup of a substance called methylmalonic acid in the body.

Symptoms

The symptoms of Methylmalonyl-CoA mutase deficiency can vary widely, but they often appear in the first year of life. They may include:

• Failure to thrive
• Developmental delay
• Vomiting
• Dehydration
• Lethargy
• Seizures
• Coma

In severe cases, the condition can lead to life-threatening metabolic crises.

Diagnosis

Methylmalonyl-CoA mutase deficiency is typically diagnosed through newborn screening tests. These tests look for elevated levels of methylmalonic acid in the blood or urine. If these levels are high, additional genetic testing may be done to confirm the diagnosis.

Treatment

There is currently no cure for Methylmalonyl-CoA mutase deficiency. Treatment is focused on managing the symptoms and preventing metabolic crises. This may involve a special diet low in certain proteins and fats, medications to reduce the levels of methylmalonic acid in the body, and in some cases, organ transplantation.

Prognosis

The prognosis for individuals with Methylmalonyl-CoA mutase deficiency varies. Some individuals may have a mild form of the condition and live into adulthood with appropriate management, while others may have a severe form of the condition and experience life-threatening metabolic crises.