Biotinidase Deficiency: Biotinidase Enzyme Analysis

Clinical Information

Biotinidase deficiency is an autosomal recessive inborn error of metabolism in which infants appear normal at birth. However, if untreated, affected infants can develop symptoms including hypotonia, ataxia, seizures, developmental delay, vision and hearing loss and cutaneous problems (eg. alopecia, dermatitis, eczema). Those diagnosed at birth should remain asymptomatic if treatment is initiated early and maintained. Biotinidase deficiency is typically detected very early because of newborn screening programs, which measure biotinidase activity in dried blood spots.

Technical Information

Biotinidase enzyme activity is determined using a p-amidobenzoic acid (PABA) colorimetric reaction that is measured by spectrophotometry at a wavelength of 546nm.

Specimen Requirements

• Plasma or serum is the accepted sample type for this test. A minimum of 3 mL whole blood collected in a sodium heparin tube or serum separator tube.
• Or blood can be centrifuged and a minimum of 1 mL plasma/serum removed and sent for analysis.

Transport Instructions

• Plasma or serum should be frozen after collection and shipped frozen, preferably on dry ice.
• Whole blood should be shipped at ambient temperature.