This is an old revision of the document!
Alpha-Feto protein, serum
Indications
- ataxic 'cerebral palsy', any type of movement disorder in early childhood, oculomotor apraxia(saccadic impairment)
Notes
- ↑ in ataxia-telangiectasia, ataxia-oculomotor apraxia 2 (AOA2) and Deoxyguanosine Kinase Deficiency(DGUOK) deficiency (hepatocerebral form of mtDNA depletion)
Alpha-fetoprotein (AFP) is present in fetal serum in concentrations up to 5,000,000 μg/l Postnatally AFP gene expression is turned down with a subsequent fall of the serum concentrations to 'adult values' of about 0.5-15 μg/l from the age of 2 years onwards. Individuals with AFP deficiency and those with hereditary persistence of AFP can however be normal. During pregnancy, AFP (in maternal serum) has long been recognized as a marker for congenital anomalies of the fetus. AFP is also a biomarker for hepatocellular carcinoma and some other malignancies.
Increased serum AFP is a biomarker for Ataxia Telangiectasia, ataxia-oculomotor apraxia 2 (AOA2) 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.
| Age group | Disorder (gene) | Increased serum AFP | Levels1) | Other laboratory markers2) |
|---|---|---|---|---|
| Infancy/childhood | Classic A-T (ATM) | All patientsc | 100–900 | Immunoglobulins, liver transaminases, chromosomal rearrangements, increased radiosensitivity |
| AOA1 (APTX) | Only in exceptional cases | 10–20 | Hypoalbuminaemia, hypercholesterolemia, and elevated serum CK | |
| Mitochondrial disorders (POLG and C10orf2) | Not systematically studied | Abnormalities in serum and CSF lactate and amino acids, urinary organic acids etc | ||
| Adolescence/adulthood | Variant A-T (ATM) | All patients3)] | 50–500 | Chromosomal rearrangements, increased radiosensitivity |
| AOA2 (SETX) | All patients4) | 10–100 | Serum CK increased | |
| AOA2 (PIK3R5) | All patients | 30–100 | Serum CK increased | |
| AOA2 (none-SETX/none-PIK3R5) | ‘By definition’ | Serum CK increased | ||
| Mitochondrial disorders (POLG and C10orf2) | Not systematically studied | Abnormalities in serum and CSF lactate and amino acids, urinary organic acids etc |
Discussion