beta-Trace protein in human cerebrospinal fluid: a diagnostic marker for N-glycosylation defects in brain.
As carbohydrate-deficient glycoprotein syndromes (CDGS) are multisystemic disorders with impaired central nervous function in nearly all cases, we tested isoforms of beta-trace protein (beta TP), a 'brain-type' glycosylated protein in cerebrospinal fluid (CSF) of nine patients with the characteristic CDGS type I pattern of serum transferrin. Whereas the serum transferrin pattern did not discriminate between the various subtypes of CDGS type I (CDGS type Ia, type Ic, and patients with unknown defect), beta TP isoforms of CDGS type Ia patients differed from that of the other CDGS type I patients. The percentage of abnormal beta TP isoforms correlated with the severity of the neurological symptoms. Furthermore, two patients are described, who illustrate that abnormal protein N-glycosylation can occur restricted to either the 'peripheral' serum or the central nervous system compartment. This is the first report presenting evidence for an N-glycosylation defect restricted to the brain. Testing beta TP isoforms is a useful tool to detect protein N-glycosylation disorders in the central nervous system.
Grünewald
S
S
Laboratory of Pediatrics and Neurology, University Hospital Nijmegen, The Netherlands.
Huyben
K
K
de Jong
J G
JG
Smeitink
J A
JA
Rubio
E
E
Boers
G H
GH
Conradt
H S
HS
Wendel
U
U
Wevers
R A
RA
D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000134:cerebrospinal fluid; D001927:Brain Diseases / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D018981:Congenital Disorders of Glycosylation / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D006031:Glycosylation; D006801:Humans; D007223:Infant; D019746:Intramolecular Oxidoreductases / Q000134:cerebrospinal fluid*; D054834:Lipocalins; D020033:Protein Isoforms / Q000134:cerebrospinal fluid
D015415:Biomarkers; D054834:Lipocalins; D020033:Protein Isoforms; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase