Biotinidase deficiency--a treatable entity.

Biotinidase deficiency is a well recognised treatable cause of a wide spectrum of progressive neurological symptoms. Recent reports have stressed the need to screen children with early onset of seizures, encephalopathy, neurodevelopmental delay, skin rash and alopecia. Enzyme estimation remains the conclusive test. We present a patient with biotinidase deficiency suspected on the above clinical grounds and diagnosed on the basis of metabolic acidosis, raised blood lactate, ketonuria and positive dinitrophenylhydrazine (DNPH) test and confirmed on urinary organic acid profile. Supplementation with biotin resulted in marked clinical improvement and normalisation of metabolic parameters. Thus the clinician should be alert to simple clinical pointers which aid in early diagnosis of these disorders.