NeuroSURE® Metabolites: Neopterin/Tetrahydrobiopterin (CSF)
Use
CSF Neopterin/Tetrahydrobiopterin (NC03) is useful for diagnosis of certain disorders of neurotransmitter metabolism. This testing may also be used for assessment of Variants of Uncertain Significance (VUS) identified during genetic testing (e.g. Next Generation Sequencing or Capillary Sequencing testing). Tetrahydrobiopterin (BH4) serves as a cofactor for the hydroxylation of phenylalanine and in the biosynthesis of biogenic amines. Deficiency of BH4 may occur as a result of mutations causing a reduction in one of the three biosynthetic enzymes, guanosine triphosphate cyclohydrolase. 6-pyruvoyl-tetrahydropterin synthase, sepiapterin reductase, or the two regenerating enzymes, pterin-4-carbinolamine dehydratase, and dihydropteridine reductase. Defects in BH4 metabolism can result in hyperphenylalaninemia and deficiency of the neurotransmitters dopamine and serotonin. Changes in CSF neopterin may also occur in deficiency of the BH4 synthesis pathway. Disorders of BH4 metabolism are characterized by a wide range of symptoms that may include developmental delay, intellectual disability, behavioral disturbances, dystonia, Parkinsonian symptoms, gait disturbances, speech delay, psychomotor impairment and ptosis.
Special Instructions
Not provided.
Limitations
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration. The test assesses Neopterin and Tetrahydrobiopterin levels, but changes in CSF neopterin can also occur due to deficiencies in the BH4 synthesis pathway which may affect the test results.
Methodology
Other
Biomarkers
Result Turnaround Time
10-14 days
Related Documents
For more information, please review the documents below
Specimen
Cerebrospinal Fluid
Volume
1.0 mL
Minimum Volume
0.5 mL
Container
Sterile screw capped vial
Collection Instructions
Sample must be collected in tube no. 3 from supplied kit (PeopleSoft No. 125218).
Storage Instructions
Freeze as soon as possible after collection at -80°C.
Causes for Rejection
Bloody CSF; received thawed
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Unstable (stability provided by manufacturer or literature reference) |
| Refrigerated | 24 hours (stability provided by manufacturer or literature reference) |
| Frozen | -20°C = 72 hours; -80°C = Indefinitely (stability provided by manufacturer or literature reference) |
Other tests from different labs that may be relevant