What is Isovaleric Acidemia?
Isovaleric Acidemia (IVA) is a rare inherited metabolic disorder in which the body is unable to properly break down the amino acid leucine. This leads to a buildup of isovaleric acid in the body, which can become toxic. It is part of a group of disorders known as organic acidemias and is typically diagnosed in infancy.
What causes Isovaleric Acidemia?
IVA is caused by mutations in the IVD gene, which provides instructions for making an enzyme called isovaleryl-CoA dehydrogenase. This enzyme is essential for breaking down leucine, a component of protein. Without this enzyme, harmful levels of isovaleric acid accumulate in the body.
What are the types of Isovaleric Acidemia?
There are two main forms:
- Acute neonatal form: Symptoms appear in the first few days of life and can be severe.
- Chronic intermittent form: Symptoms appear later in infancy or childhood, often during times of stress, illness, or fasting.
What are the symptoms of Isovaleric Acidemia?
Symptoms can range from mild to severe and may include:
- Vomiting
- Poor feeding
- Lethargy
- Seizures
- A characteristic “sweaty feet” odor
- Developmental delays
- Coma in severe cases
How is Isovaleric Acidemia diagnosed?
IVA is typically diagnosed through newborn screening tests. Further confirmation can be done using:
- Blood and urine tests to detect abnormal levels of isovaleric acid
- Genetic testing to identify IVD gene mutations
- Enzyme activity assays
What is the treatment for Isovaleric Acidemia?
Treatment aims to reduce the buildup of toxic substances and manage symptoms. It may include:
- Low-protein diet to limit leucine intake
- Special medical formulas that are leucine-free
- L-carnitine or glycine supplements to help remove excess isovaleric acid
- Emergency treatment during illness to prevent metabolic crises, including IV fluids and glucose
What is the outlook for people with Isovaleric Acidemia?
With early diagnosis and proper management, individuals with IVA can live healthy lives. However, without treatment, the condition can lead to life-threatening complications, especially during illness or fasting.
