Acid Sphingomyelinase Activity in Dried Blood Spot from Neonatal Intensive Care Unit-Admitted Neonates: A Pilot Study for Expanded Newborn Screening in Japan.

The mean acid sphingomyelinase activity was 3.7 ± 1.2 μmol/h/L (95% confidence interval, 3.54-3.84; range, 1.7-11.6), with a right-skewed distribution.

Acid sphingomyelinase activity correlated positively with birth weight (r = 0.184, p = 0.0039), gestational age (r = 0.219, p = 0.0006), and lymphocyte count (ρ = 0.394, p = 0.0089) and negatively with hematocrit (ρ = -0.372, p = 0.014).