3 hydroxyisobutyric aciduria

A rare metabolic disorder

3-Hydroxyisobutyric aciduria
Synonyms	3-HIBA
Pronounce	N/A
Specialty	N/A
Symptoms	Developmental delay, hypotonia, metabolic acidosis
Complications	N/A
Onset	Infancy
Duration	Chronic
Types	N/A
Causes	Genetic mutation
Risks	Family history
Diagnosis	Urine organic acid analysis, genetic testing
Differential diagnosis	Other organic acidurias
Prevention	N/A
Treatment	Dietary management, supplementation
Medication	N/A
Prognosis	Variable
Frequency	Rare disease
Deaths	N/A

3-Hydroxyisobutyric aciduria is a rare metabolic disorder characterized by the accumulation of 3-hydroxyisobutyric acid in the body. This condition is caused by a deficiency in the enzyme responsible for the metabolism of valine, an essential amino acid.

Pathophysiology

3-Hydroxyisobutyric aciduria results from a defect in the valine catabolic pathway. Normally, valine is broken down into several intermediates, one of which is 3-hydroxyisobutyric acid. In individuals with this disorder, the enzyme responsible for further metabolizing 3-hydroxyisobutyric acid is deficient or absent, leading to its accumulation in the body.

Clinical Presentation

Patients with 3-hydroxyisobutyric aciduria may present with a variety of symptoms, which can include:

• Developmental delay
• Hypotonia
• Seizures
• Metabolic acidosis

The severity and range of symptoms can vary widely among affected individuals.

Diagnosis

The diagnosis of 3-hydroxyisobutyric aciduria is typically made through urine organic acid analysis, which reveals elevated levels of 3-hydroxyisobutyric acid. Genetic testing can confirm the diagnosis by identifying mutations in the gene responsible for the enzyme deficiency.

Treatment

There is currently no cure for 3-hydroxyisobutyric aciduria. Treatment is primarily supportive and may include:

• Dietary management to limit valine intake
• Physical therapy to address developmental delays and hypotonia
• Anticonvulsant medications to control seizures

Prognosis

The prognosis for individuals with 3-hydroxyisobutyric aciduria varies depending on the severity of the enzyme deficiency and the effectiveness of supportive treatments. Early intervention and management can improve outcomes for some patients.

Related pages

• Metabolic disorder
• Valine
• Organic acidemia

NIH genetic and rare disease info

• NIH info on 3 hydroxyisobutyric aciduria

3 hydroxyisobutyric aciduria is a rare disease.