Biotin-responsive infantile encephalopathy: EEG-polygraphic study of a case
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V Colamaria1, A B Burlina, D Gaburro
1Department of Paediatrics, University of Verona, Italy.
Insights
This study reports a case of infant biotinidase deficiency presenting with severe neurological symptoms. Prompt biotin supplementation led to dramatic improvement, suggesting its therapeutic potential for similar conditions.
Area of Science:
- Biochemistry
- Pediatric Neurology
- Genetics
Background:
- Biotinidase deficiency is an inherited metabolic disorder affecting biotin metabolism.
- Early diagnosis and treatment are crucial to prevent severe neurological sequelae.
Observation:
- An infant presented with progressive lethargy, sparse hair, autistic-like behavior, myoclonias, and drug-resistant seizures.
- Laboratory findings included increased urinary 2-ketoglutaric acid and low serum biotinidase activity.
- EEG revealed multifocal abnormalities and documented various seizure types, including tonic-clonic fits and myoclonias.
Findings:
- The patient exhibited profoundly deficient serum biotinidase activity.
- Treatment with biotin (10 mg daily) resulted in a dramatic improvement of all neurological symptoms and signs.
- Metabolic investigations showed elevated 2-ketoglutaric acid and 3-hydroxyisovaleric acid, consistent with biotin deficiency.
Implications:
- This case highlights the importance of considering biotinidase deficiency in infants with unexplained neurological symptoms.
- The findings support a therapeutic trial of biotin for drug-resistant infantile seizures, particularly those with features suggestive of metabolic disorders.
- Early biotin supplementation can prevent or reverse severe neurological damage in biotinidase deficiency.
Abstract:
A case of an infant suffering from progressive lethargy, sparse scalp hair, autistic-like behavior, myoclonias, and drug-resistant generalized seizures is reported. Laboratory investigations revealed, in the absence of metabolic acidosis, an increased urinary excretion of 2-ketoglutaric acid and a small peak of 3-hydroxyisovaleric acid. The serum biotinidase activity was 0.15 nmol min-1 ml-1 (normal range 5.2 +/- 0.9) in the propositus and 0.310 and 0.420 in her father and mother, respectively. The interictal EEG showed multifocal abnormalities; numerous seizures were recorded, with the pattern of true tonic-clonic fits, exceptional in infancy. Also myoclonias, auditory myoclonus, and repetitive startles were documented. Because of dramatic improvement of all symptoms and signs after starting biotin (5 mg twice daily), the authors suggest a therapeutical trial in all drug-resistant infantile seizures.