Abstract
Biotinidase deficiency (BD) is a rare treatable cause of neurometabolic disorders.
It is an autosomal recessive disorder that manifests with cutaneous and neurological
manifestations. Spinal cord involvement is uncommon with only a few cases reported
in the literature. A 6-year-old female child presented with progressive difficulty
in walking since 2 months. At 6 months of age, the child was elsewhere evaluated for
global developmental delay and suspected as metabolic disorders and started on megavitamins,
following which the child was improved. For the past 2 years, she has stopped medicines.
On examination, irritable, alopecia, eczema, hypotonia, and power of two-fifths in
all four limbs, and exaggerated deep tendon reflexes. The magnetic resonance imaging
(MRI) brain and spine showed T2/fluid-attenuated inversion recovery (FLAIR) hyperintensities
in periaqueductal gray matter, dorsal midbrain, pons, medulla, and cervical cord.
She was suspected to have BD and confirmed by low enzyme levels and pathogenic variant
in BTD. She was started on biotin supplements that resulted clinically dramatic improvement
and MRI became normal within 4 weeks. Any child presenting with acute flaccid paralysis
with brainstem and spinal cord noncompressive lesions on MRI, rare treatable conditions
like BD should be considered in developing countries, like India, where still no universal
newborn screening facilities are available.
Keywords
biotinidase deficiency - demyelination - spinal cord - acute flaccid paralysis - inborn
errors of metabolism
