Propionic Acidemia

What is propionic acidemia?

Propionic acidemia is a rare inherited condition that is a subtype of organic acidemia. It occurs when the body is unable to process certain parts of proteins and lipids properly. This leads to the buildup of abnormal levels of toxic substances in tissues and in the blood, leading to all kinds of associated health problems, namely, episodes of illness called metabolic crises.

What causes propionic acidemia?

Propionic acidemia is caused by a deficiency of propionyl CoA carboxylase, which is an enzyme involved in the catabolism of amino acids in certain proteins. This deficiency is inherited in an autosomal recessive pattern.

What are the symptoms of propionic acidemia?

Signs and symptoms of propionic acidemia generally develop within the first few days after birth. These include:

• Poor feeding
• Vomiting
• Loss of appetite
• Weak muscle form
• Lack of energy
• Seizures

Without appropriate treatment, propionic acidemia can lead to coma or even death.

Later on, patients with propionic acidemia may experience constipation, hyperammonemia, and intellectual disability, although the condition is overall usually less severe.

How is propionic acidemia diagnosed?

In some cases, propionic acidemia may be diagnosed before birth by measuring the cbaby’s amniotic fluid.

Newborns may be screened for propionic acidemia used the ACTion (ACT) sheet and/or “Baby’s First Test,” and most diagnoses are confirmed in the first weeks of life using laboratory studies on white blood cells or cultured skin cells to reveal the activity of the propionyl CoA carboxylase enzyme.

What are the available treatments for propionic acidemia?

Appropriate dietary management is the main treatment for propionic acidemia, specifically a low-protein diet which will help prevent a metabolic crisis. In addition, oral biotin or carnitine supplementation may be recommended, and fasting should be avoided.

During acute episodes of the condition, fluid and electrolyte therapy may be used alongside supportive measures (anti-bacterial medications, hemodialysis).

Where can I find more information about propionic acidemia?

• NIH
• National Organization for Rare Disorders (NORD)