Determination of psychosine concentration in dried blood spots from newborns that were identified via newborn screening to be at risk for Krabbe disease.

[krabbe disease]

New York State has screened over 1 .2 million newborns for Krabbe disease , and we identified 4 newborns with infantile Krabbe disease . In addition , 6 other newborns were identified with very low galactosylcerebrosidase (GALC ) activity . Because these patients remain asymptomatic , we investigated whether psychosine levels could be a useful marker for disease .HPLC-MS /MS methodology was used to determine the psychosine concentrations in dried blood spots (DBS ) collected from the following cohorts : known Krabbe patients , screened babies that were determined to have infantile Krabbe disease , asymptomatic infants with low GALC activity , and normal controls .The psychosine concentrations from the known Krabbe patients ranged from 7 to 50 ng /ml . Newborns identified by screening who were confirmed with infantile Krabbe disease ranged from 23 to 73 ng /ml . Asymptomatic individuals with low GALC activity had concentrations ranging from 1 .7 to 5 .7 ng /ml . Concentrations in newborns with normal GALC activity were all <3 ng /ml .The psychosine concentrations in DBS from confirmed infantile patients are at least four times higher than the asymptomatic newborns and nearly an order of magnitude greater than normal newborns . Further studies are needed to determine if psychosine can be used as a predictor of disease status /progression in screen positive newborns .