Glutaric aciduria type I (GA-I)
Glutaric aciduria type I (GA-I)
Alternative name
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Glutaryl-CoA dehydrogenase deficiency
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About the condition
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GA-I is an organic acid disorder. It is a hereditary disease that is caused by a missing enzyme needed to metabolise the amino acids lysine, hydroxylysine and tryptophan. There is specific damage to the basal ganglia in the brain.
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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 glutaryl-CoA dehydrogenase, which metabolises lysine, hydroxylysine and tryptophan.
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Symptoms if untreated
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- Vomiting
- Macrocephaly
- Encephalopathic crises
- Movement disorder, dystonia
- Seizures
- Coma and death possible
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Metabolites on bloodspot screening
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- Increased glutarylcarnitine (C5DC)
- Increased C5DC/C5OH ratio
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Diagnostic tests
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- Plasma acylcarnitine profile
- Plasma amino acids
- Urine organic acids
- GCDH gene analysis
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Treatment
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- Lysine and tryptophan restricted diet
- Carnitine supplementation
- Riboflavin supplementation
- IV glucose and supportive measures during crisis episodes
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Screening issues
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A proportion of patients are "low excretors" and biochemical detection may not be reliable.
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