Profound biotinidase deficiency in two asymptomatic adults

Barry Wolf*, Karen Norrgard, Robert J. Pomponio, Donald M. Mock, Julie R. Secor McVoy, Kristin Fleischhauer, Steven Shapiro, Miriam G. Blitzer, Jeanne Hymes

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

40 Scopus citations


Biotinidase deficiency is an autosomal-recessive disorder of biotin recycling. Children with profound biotinidase deficiency usually have neurological and cutaneous symptoms in early childhood, but they may not develop symptoms until adolescence. We now report on a man and a woman with profound biotinidase deficiency who are asymptomatic and who were diagnosed only because their biotinidase-deficient children were identified by newborn screening. These adults have never exhibited symptoms of the disorder and are homozygous for two different mutations resulting in different aberrant enzymes. There is no evidence of an increased dietary intake of biotin to explain why they have remained asymptomatic. Although these adults may still be at risk for developing symptoms, they could represent a small group of individuals with profound biotinidase deficiency who will never develop clinical problems. Their lack of symptoms suggests that there are probably epigenetic factors that protect some enzyme-deficient individuals from developing symptoms. These individuals broaden the spectrum of expression of biotinidase deficiency.

Original languageEnglish (US)
Pages (from-to)5-9
Number of pages5
JournalAmerican Journal of Medical Genetics
Issue number1
StatePublished - Nov 28 1997


  • Biotin
  • Biotinidase
  • Biotinidase deficiency
  • Hydrolase
  • Mutations
  • Transferase

ASJC Scopus subject areas

  • Genetics(clinical)


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