Newborn screening for biotinidase deficiency in Brazil: Biochemical and molecular characterizations

E. C. Neto*, J. Schulte, R. Rubim, E. Lewis, J. DeMari, C. Castilhos, A. Brites, R. Glugliani, K. P. Jensen, B. Wolf

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Scopus citations


Biotinidase deficiency is an inherited metabolic disorder characterized by neurological and cutaneous symptoms. Fortunately, it can be treated and the symptoms prevented by oral administration of the vitamin biotin. Using dried blood-soaked filter paper cards, biotinidase activity was determined in the sera of 225,136 newborns in Brazil. Mutation analysis performed on DNA from 21 babies with low serum biotinidase activity confirmed that 3 had profound biotinidase deficiency (less than 10% of mean normal sera biotinidase activity), 10 had partial biotinidase deficiency (10 to 30% of mean normal serum activity), 1 was homozygous for partial biotinidase deficiency, 4 were heterozygous for either profound or partial deficiency, and 3 were normal. Variability in serum enzyme activities and discrepancies with mutation analyses were probably due to inappropriate handling and storage of samples sent to the laboratory. Obtaining an appropriate control serum at the same time as that of the suspected child will undoubtedly decrease the false-positive rate (0.09%). Mutation analysis can be used to confirm the genotype of these children. The estimated incidence of biotinidase deficiency in Brazil is about 1 in 9,000, higher than in most other countries. Screening and treatment of biotinidase deficiency are effective and warranted. These results strongly suggest that biotinidase deficiency should be included in the newborn mass screening program of Brazil.

Original languageEnglish (US)
Pages (from-to)295-299
Number of pages5
JournalBrazilian Journal of Medical and Biological Research
Issue number3
StatePublished - Mar 2004


  • Biotinidase
  • Biotinidase deficiency
  • Enzyme assay
  • Mutations
  • Newborn screening

ASJC Scopus subject areas

  • Biophysics
  • Neuroscience(all)
  • Biochemistry
  • Physiology
  • Immunology
  • Pharmacology, Toxicology and Pharmaceutics(all)
  • Cell Biology


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