Worldwide survey of neonatal screening for biotinidase deficiency

Summary Neonatal screening for biotinidase deficiency has been conducted in 14 countries since 1984. To 31 December 1990, 8 532 617 newborns were screened. One hundred and forty‐two infants with biotinidase deficiency were identified; 76 infants with profound deficiency (<10% of mean normal serum activity) and 66 infants with partial deficiency (10–30% of mean normal activity). The estimated incidence of profound biotinidase deficiency is 1:112 271 (1:85 000 to 1:145 000; 95% confidence limits) and the incidence of partial deficiency is 1:129 282 (1:112 700 to 1:177 000). The incidence of combined profound and partial deficiency is 1:60 089 newborns (1:49 500 to 1:73 100). The estimated frequency of the allele for biotinidase deficiency is 0.004 and an estimated 1 in 123 individuals is heterozygous for the disorder.