Organic Acidaemias


Isovaleric Aciduria (IVA)



Isovaleric Aciduria is an inherited autosomal recessive metabolic disorder, which 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. Isovaleric acidemia (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 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. Oral carnitine and glycine supplements may also be prescribed. Infections and fevers are treated aggressively to prevent muscle breakdown and subsequent release of stored proteins. This is achieved by limiting dietary protein during periods of illness and increasing the intake of carbohydrates. 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