Isovaleric acidaemia (IVA)
Isovaleric acidaemia (IVA)
Alternative name
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Isovaleryl-CoA dehydrogenase deficiency
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About the condition
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IVA is an organic acid disorder. It is a hereditary disease that is caused by a missing enzyme needed to convert protein into energy.
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Inheritance
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Autosomal recessive
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Year screening started in WA
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2005 |
Incidence in Australia
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Currently unknown
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Enzyme defect
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Deficiency of the enzyme isovaleryl-CoA dehydrogenase, which catalyses an early step in the metabolism of the branched-chain amino acid leucine.
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Symptoms if untreated
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- Episodic ketoacidosis
- Vomiting
- Cytopaenia
- Coma and death possible
- ‘Sweaty feet’ odour
- A chronic intermittent form presents later in childhood
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Metabolites on bloodspot screening
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Increased isovalerylcarnitine (C5).
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Diagnostic tests
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- Plasma acylcarnitine profile
- Urine organic acids
- IVD gene analysis
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Treatment
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- Low-protein diet (leucine-restricted)
- Carnitine supplementation
- Glycine supplementation
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Screening issues
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There are milder variants of uncertain clinical significance.
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