3-Hydroxyisobutyric aciduria is a rare metabolic condition in which the body is unable to breakdown certain amino acids (the building blocks of protein). This leads to a toxic buildup of particular acids known as organic acids in the blood (organic acidemia), tissues and urine (organic aciduria). Signs and symptoms of 3-hydroxyisobutyric aciduria include developmental delay, characteristic facial features and brain abnormalities. The exact underlying cause is not well understood; however, researchers believe some cases are caused by changes (mutations) in the ALDH6A1 gene and inherited in an autosomal recessive manner. Because it is so rare, there is limited evidence to support the effectiveness of treatment, but a protein-restricted diet and carnitine supplementation have been tried with varying degrees of success.
