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.

• Developmental delay
• Intellectual disability
• Failure to thrive
• Characteristic facial features including a long philtrum and small, low-set ears
• Unusually small head (microcephaly)
• Congenital brain abnormalities
• Nausea
• Diarrhea
• Dehydration
• Lethargy

The severity of the condition can also vary significantly from person to person. Some affected people may only experience mild attacks of vomiting with normal development, while others experience failure to thrive with severe intellectual disability and early death.

ALDH6A1 gene. This gene encodes an enzyme called methylmalonate semialdehyde dehydrogenase, which helps the body break down certain amino acids (the building blocks of protein) found in food. If this gene isn't working properly, the body is unable to break down the amino acids valine and thymine which leads to a build-up of toxic substances in the body and the many signs and symptoms of 3-hydroxyisobutyric aciduria.

ALDH6A1 gene are inherited in an autosomal recessive manner. This means that to be affected, a person must have a mutation in both copies of the responsible gene in each cell. The parents of an affected person usually each carry one mutated copy of the gene and are referred to as carriers. Carriers typically do not show signs or symptoms of the condition. When two carriers of an autosomal recessive condition have children, each child has a 25% (1 in 4) risk to have the condition, a 50% (1 in 2) risk to be a carrier like each of the parents, and a 25% chance to not have the condition and not be a carrier.

There is no cure for 3-hydroxyisobutyric aciduria. Because it is so rare, there is limited evidence to support the effectiveness of treatment. However, affected people have been treated with a protein-restricted diet and carnitine supplementation with varying degrees of success.