Test Details
Methodology
High-pressure liquid chromatography (HPLC)
Result Turnaround Time
10 - 14 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
CSF Pyridoxal 5'-phosphate is useful for diagnosis of disorders leading to low CSF levels of this cofactor. This testing may also be used for assessment of Variants of Uncertain Significance (VUS) identified during genetic testing (eg. Next Generation Sequencing or Capillary Sequencing testing). Pryridoxal 5' phosphate (PLP) (a member of the vitamin B6 family) is required as a cofactor for more than 100 different enzymes in the body. These may involve the metabolism of various neurotransmitters and amino acids. Inadequate PLP may occur due to genetic, nutritional deficiencies as well as reaction with various drugs. Inherited disorders that affect the CSF PLP level include pyriodx(am)ine phosphate oxidase (PNPO) deficiency, alpha amnioadipic semialdehyde dehydrogenase deficiency, hyperprolinermia type 2 and hypophoshatasia due to alkaline phosphatase deficiency.
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.
Specimen Requirements
Specimen
Cerebrospinal fluid (CSF)
Volume
1.0 mL
Minimum Volume
0.5 mL
Container
Sterile screw capped vial
Collection Instructions
Collect entire sample into a single sterile tube.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | Unstable (stability provided by manufacturer or literature reference) |
Refrigerated | Unstable (stability provided by manufacturer or literature reference) |
Frozen | -20°C = 72 hours; -80°C = Indefinite (stability provided by manufacturer or literature reference) |
Freeze/thaw cycles | None (stability provided by manufacturer or literature reference) |
Storage Instructions
Freeze immediately.
Causes for Rejection
Bloody CSF; received thawed