Two patients who developed infantile spasms at 1 month of age and were found to have biotinidase deficiency are reported from the Hacettepe Children’s Hospital, Ankara, Turkey. The parents were consanguineous. Corticotropin had been prescribed initially with partial seizure control. When evaluated at 3 months because of seizure exacerbation, the infants were lethargic and hypotonic, one had alopecia and seborrheic dermatitis and the other’s scalp hair was sparse. Metabolic and lactic acidosis developed, and biotinidase deficiency was suspected and confirmed. Both infants responded promptly to biotin, and blood pH and bicarbonate became normal within hours. At 5-11 month follow-up, seizures had not recurred, the EEG and neurologic examinations were normal, but the developmental mental scores on the Bayley Scale were severely retarded. 
COMMENT. Biotin responsive late onset multiple carboxylase deficiency is an autosomal recessive inherited disorder manifested by seizures, alopecia, skin rash, hypotonia, ataxia, hearing loss, and developmental retardation. Lactic acidosis and organic aciduria may be delayed. If untreated the symptoms become progressively worse and coma and death may occur. Symptoms respond rapidly to biotin 5-10 mg daily, but neurologic damage may be irreversible. (Progress in Pediatric Neurology. Chicago, PNB Publishers, 1991, pp547-550). Biotin deficiency should be considered as a possible etiology of infantile spasms. A therapeutic trial of biotin has been recommended in all drug resistant infantile seizures, pending the results of enzyme and metabolic tests. (Ped Neur Briefs Nov 1989).
Infantile spasms or myoclonic seizures were present in 16% of 30 infants with biotinidase deficiency reported from the Medical College of Virginia, Richmond, VA . The authors advocated neonatal mass screening for early diagnosis and avoidance of neurologic damage. (Ped Neur Briefs July 1993;7:51).