The impact of hematocrit, punch location, and cellular interference on neonatal screening for biotinidase deficiency

Our results demonstrated a significant systematic bias: Peripheral punches yielded higher biotinidase activity than central punches across all sample types (13.36%-16.61% difference, p20% higher values at the critical biotinidase activity-50 U level. Crucially, leukocyte depletion resulted in a statistically significant decrease in measured activity (~10.6%, p.