A newborn screening method for cerebrotendinous xanthomatosis using bile alcohol glucuronides and metabolite ratios.
Cerebrotendinous xanthomatosis (CTX) is a treatable neurodegenerative metabolic disorder of bile acid synthesis in which symptoms can be prevented if treatment with chenodeoxycholic acid supplementation is initiated early in life, making CTX an excellent candidate for newborn screening. We developed a new dried blood spot (DBS) screening assay for this disorder on the basis of different ratios between the accumulating cholestanetetrol glucuronide (tetrol) and specific bile acids/bile acid intermediates, without the need for derivatization. A quarter-inch DBS punch was extracted with methanol, internal standards were added, and after concentration the extract was injected into the tandem mass spectrometer using a 2 min flow injection analysis for which specific transitions were measured for cholestanetetrol glucuronide, taurochenodeoxycholic acid (t-CDCA), and taurotrihydroxycholestanoic acid (t-THCA). A proof-of-principle experiment was performed using 217 Guthrie cards from healthy term/preterm newborns, CTX patients, and Zellweger patients. Using two calculated biomarkers, tetrol:t-CDCA and t-THCA:tetrol, this straightforward method achieved an excellent separation between DBSs of CTX patients and those of controls, Zellweger patients, and newborns with cholestasis. The results of this small pilot study indicate that the tetrol:t-CDCA ratio is an excellent derived biomarker for CTX that has the potential to be used in neonatal screening programs.
Department of Clinical Chemistry and Pediatrics, Laboratory of Genetic Metabolic Diseases, Academic Medical Center, Amsterdam, The Netherlands f.m.vaz@amc.nl.
Frédéric M
FM
Vaz
Department of Clinical Chemistry and Pediatrics, Laboratory of Genetic Metabolic Diseases, Academic Medical Center, Amsterdam, The Netherlands.
Albert H
AH
Bootsma
Department of Clinical Chemistry and Pediatrics, Laboratory of Genetic Metabolic Diseases, Academic Medical Center, Amsterdam, The Netherlands.
Willem
W
Kulik
Department of Neurology, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands.
Aad
A
Verrips
Department of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Centre, Nijmegen, The Netherlands.
Ron A
RA
Wevers
Centre for Infectious Diseases Research, Diagnostics and Screening, National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
Peter C
PC
Schielen
Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR.
Andrea E
AE
DeBarber
Department of Pediatrics, Center for Lysosomal and Metabolic Diseases, Erasmus Medical Center, Rotterdam, The Netherlands.
Hidde H
HH
Huidekoper
D000293:Adolescent; D001647:Bile Acids and Salts / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D002779:Cholestasis / Q000150:complications; D059788:Dried Blood Spot Testing / Q000379:methods*; D005260:Female; D020719:Glucuronides / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening / Q000379:methods*; D019294:Xanthomatosis, Cerebrotendinous / Q000097:blood* / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism
D001647:Bile Acids and Salts; D020719:Glucuronides
CYP27A1; bile acid metabolism; bile acids and salts biosynthesis; inborn errors of metabolism; tandem mass spectrometry