Implementation of newborn screening for Krabbe disease: population study and cutoff determination.
OBJECTIVE
The aim of this study was to develop a newborn screening algorithm for Krabbe disease.


METHODS
We measured the galactocerebrosidase activity of 139,074 anonymous newborns, 56 known carriers, and 16 Krabbe patients using a tandem mass spectrometry method. The activities were converted to percentages of daily mean activity (%DMA), and the results from diseased and normal populations were used to establish cutoffs.


RESULTS
The absolute activities for the newborns ranged from 0.17 to 355 micromol/L h (N=139,074) and activities for Krabbe-positive controls ranged from 0.08 to 0.48 micromol/L h (N=16, n=91 measurements) while activities for carriers ranged from 0.28 to 2.71 micromol/L h (N=56, n=72 measurements). Cutoffs were set based on results from Krabbe-positive and carrier controls and the newborn population distribution.


CONCLUSIONS
The algorithm and cutoffs we propose provided 100% detection of all positive controls with 60/100,000 screen positive results predicted. In the course of this study, one anonymous newborn was predicted to have Krabbe disease based on enzyme activity and subsequent DNA analysis.
Orsini
Joseph J
JJ
Newborn Screening Program, New York State Department of Health, Wadsworth Center, P.O. Box 509, Albany, NY 12201-0509, USA. jjo01@health.state.ny.us
Morrissey
Mark A
MA
Slavin
Laura N
LN
Wojcik
Matthew
M
Biski
Chad
C
Martin
Monica
M
Keutzer
Joan
J
Zhang
X Kate
XK
Chuang
Wei-Lien
WL
Elbin
Carole
C
Caggana
Michele
M