Isovaleric Aciduria (IVA)


Isovaleric Aciduria (IVA) is an inherited autosomal recessive metabolic disorder. It is caused by a genetic defect where the isovaleryl-CoA dehydrogenase is either missing or not working properly to metabolise leucine. Consuming foods containing leucine results in a substance called isovaleric acid building up within the blood. IVA was the first condition to be recognised as an organic acidemia.


The condition is diagnosed during newborn screening via the heel prick test, taken 48-72 hours after birth.


1:250,000 estimated worldwide

Treatment for Isovaleric Aciduria

Treatment of Isovaleric Aciduria involves low protein dietary modification to restrict the intake of leucine. A leucine-free formula may also be given. These specially formulated powders contain a balanced mix of essential and non-essential amino acids, vitamins and minerals, with minimal carbohydrates. Doctors may also prescribe oral carnitine and glycine supplements. They aggressively treat infections and fevers to prevent muscle breakdown and the subsequent release of stored proteins. This is achieved by limiting dietary protein during periods of illness and increasing carbohydrate intake. A range of special low-protein food products is available. The dose of carnitine is also increased at these times.

Support Links & Materials

Organic Acidurias Handbook

OA Fruit and Veg Counting Lists

OA General Protein Counting Lists

TEMPLE Resource: Isovaleric Aciduria (IVA) Book