[Results of a pilot study of neonatal screening for congenital biotinidase deficiency]

Biotinidase activity was determined in a pilot study of 78,000 dried blood samples on filter paper. In the assay the liberation of p-aminobenzoic-acid from biotinyl-p-aminobenzoic-acid by biotinidase is tested. One boy was identified to be with biotinidase deficiency. Transient reduction of biotinidase activity to virtually negative test results was observed in 8 preterm babies (recall: 0,01%). Specificity and sensitivity of the test were nearly 100%. We suggest that screening for biotinidase deficiency should be incorporated into existing neonatal screening programs for inborn errors of metabolism. This suggestion is based on the ease of testing, the necessity for presymptomatic laboratory diagnosis, and on the effectiveness of early treatment of the multiple carboxylase deficiency caused by defective biotinidase.