Treatable Intellectual Disability

HHH Syndrome

BIOCHEMICAL DEFECT

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DIAGNOSIS

Gene
SLC25A15 (AR)

Diagnostic Test
Plasma Amino Acids

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SIGNS & SYMPTOMS

Neurological
Spasticity

Non-Neurological
Coagulopathy

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THERAPY

Treatment
Dietary Protein Restriction, Ornithine Supplement, Sodium Benzoate, Phenylacetate

Level of Evidence / Clinical Practice
4 / Standard of Care


Treatment Effect
Prevents metabolic decompensation;
stabilizes clinical deterioration; improves behaviour, seizure control, neurological & systemic manifestations

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HHHsyndrome

HHH Syndrome (Hyperornithinemia, Hyperammonemia, Homocitrullinuria)

is a very rare autosomal recessive genetic disease due to defective transportation of ornithine into the mitochondria. This causes a functional deficiency in ornithine transcarbamoylase and ornithine aminotransferase. Onset may be neonatal, infantile or juvenile (until adolescence). Symptoms vary from seizures, vomiting with protein intolerance, and developmental delay to the most severe form with coma due to hyperammonemia. (Source: Orphanet)

No information available from this source.

This disease is not (yet) listed on their website.