title: Alpha-fetoprotein, a fascinating protein and biomarker in neurology.
abstract: Alpha-fetoprotein (AFP) is present in fetal serum in concentrations up to 5,000,000 μg/l. After birth, AFP gene expression is turned down with a subsequent fall of the serum concentrations of this albumin-like protein to 'adult values' of circa 0.5-15 μg/l from the age of 2 years onwards. Irrespective of its assumed important functions, individuals with AFP deficiency appear fully healthy. The other way around, the presence of AFP in the circulation after the first years of life doesn't seem to harm, since individuals with 'hereditary persistence of AFP' are also without clinical abnormalities. During pregnancy, AFP (in maternal serum) has long been recognized as a marker for congenital anomalies of the fetus. Equally well known is AFP as biomarker for hepatocellular carcinoma and some other malignancies. There are at least four neurodegenerative disorders, all inherited as autosomal recessive traits and characterized by the presence of cerebellar ataxia, abnormal ocular movements, and neuropathy, for which an elevated concentration of serum AFP is an important diagnostic biomarker. The availability of a reliable biomarker is not only important during screening or diagnostic processes, but is also relevant for objective follow-up during (future) therapeutic interventions.
authors.affiliation: Department of Pediatric Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. Electronic address: j.schieving@neuro.umcn.nl.
authors.forename: J H
authors.initials: JH
authors.lastname: Schieving
authors.affiliation: Department of Pediatrics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: de Vries
authors.affiliation: Department of Obstetrics and Gynaecology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: J M G
authors.initials: JM
authors.lastname: van Vugt
authors.affiliation: Department of Pediatrics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Weemaes
authors.affiliation: Department of Internal Medicine, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: van Deuren
authors.affiliation: Department of Neurology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Nicolai
authors.affiliation: Department of Laboratory Medicine, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: R A
authors.initials: RA
authors.lastname: Wevers
authors.affiliation: Department of Pediatric Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: M A
authors.initials: MA
authors.lastname: Willemsen
mesh_terms: D000818:Animals; D001259:Ataxia / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism*; D005260:Female; D006801:Humans; D019636:Neurodegenerative Diseases / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D011247:Pregnancy; D000509:alpha-Fetoproteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D000509:alpha-Fetoproteins
keywords: AFP deficiency; Alpha-fetoprotein (AFP); Ataxia Telangiectasia; Ataxia with oculomotor apraxia type 1 and 2; Diagnostic biomarker; Hereditary persistence of AFP; Mitochondrial disorders