Isobutyryl-coenzyme A dehydrogenase deficiency is a rare metabolic disorder in which the body is unable to process certain amino acids properly.

If a mutation in the ACAD8 gene reduces or eliminates the activity of this enzyme, the body is unable to break down valine properly.

The signs and symptoms may not appear until later in infancy or childhood and can include poor feeding and growth (failure to thrive), a weakened and enlarged heart (dilated cardiomyopathy), seizures, and low numbers of red blood cells (anemia).

Another feature of this disorder may be very low blood levels of carnitine (a natural substance that helps convert certain foods into energy).

Isobutyryl-CoA dehydrogenase deficiency may be worsened by long periods without food (fasting) or infections that increase the body's demand for energy.