摘要
Biotinidase deficiency is an inherited metabolic disorder characterized by ina bility to recycle protein-bound biotin. It usually presents with ataxia and sei zures, though atypical presentations have also been described. We report a 15-m onth-old boy with profound biotinidase deficiency who presented with laryngeal stridor and subsequently developed severe ataxia and lactic acidosis. Subsequent ly, it was discovered that the patient’s newborn screening test for biotinidase activity had been inconclusive, but confirmatory testing had not been done. Bra in magnetic resonance imaging showed multiple white matter non-enhancing T2 hyp erintensities, which largely resolved following 6 months of biotin therapy; howe ver, there was residual deafness and mental retardation. Conclusion:An argument is made for universal newborn screening in biotinidase deficiency and improved m echanisms for follow-up of positive screens, because delay in diagnosis results in irreversible morbidity, newborn screening is cost effective, and early thera py prevents the neurologic sequelae.
Biotinidase deficiency is an inherited metabolic disorder characterized by ina bility to recycle protein-bound biotin. It usually presents with ataxia and sei zures, though atypical presentations have also been described. We report a 15-m onth-old boy with profound biotinidase deficiency who presented with laryngeal stridor and subsequently developed severe ataxia and lactic acidosis. Subsequent ly, it was discovered that the patient's newborn screening test for biotinidase activity had been inconclusive, but confirmatory testing had not been done. Bra in magnetic resonance imaging showed multiple white matter non-enhancing T2 hyp erintensities, which largely resolved following 6 months of biotin therapy; howe ver, there was residual deafness and mental retardation. Conclusion:An argument is made for universal newborn screening in biotinidase deficiency and improved m echanisms for follow-up of positive screens, because delay in diagnosis results in irreversible morbidity, newborn screening is cost effective, and early thera py prevents the neurologic sequelae.
