Why screen newborns for profound and partial biotinidase deficiency?

Abstract

Newborn screening for biotinidase deficiency is currently performed throughout the United States and inmany countries of the world. However, there are still many countries that do not screen for the disorder. After learning howmany countries are still not screening for biotinidase deficiency, and after I received the comments on a recently submitted publication, I was compelled to address twomajor concerns about newborn screening for the disorder. The first is why should a country screen their newborns for profound biotinidase deficiency (less than 10% of mean normal serum enzyme activity)? The second is, if a country screens their newborns for profound biotinidase deficiency, why should they also screen for partial biotinidase deficiency (between10% and 30% of mean normal serum enzyme activity)? Before addressing these issues, Iwould like to state that over thepast 32 years, my research has focused on the study of the clinical, biochemical and molecular aspects of biotinidase deficiency. Even though my laboratory developed the colorimetric assay for biotinidase activity using blood-soaked filter paper cards, and we conducted the first newborn screening program in Virginia, I have not received, nor do I currently receive, any compensation for any aspect of newborn screening of the disorder. This being said, I would like to address the above questions. Why screen newborns for profound biotinidase deficiency? Since the discovery of biotinidase deficiency in our laboratory in 1982 [1,2], there has been a rapid transition from the development of a colorimetric method for determining biotinidase activity using blood-soaked filter paper spots [3] to the demonstration of the feasibility of performing