Test Details
Methodology
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
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 Alpha aminoadipic semialdehyde is useful for diagnosing pyridoxine-dependent seizures (PDS) and folinic acid-responsive seizures (FRS). 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). Pyridoxine dependent seizures is a genetic disorder characterized by seizures in neonates or infants up to 3 years of age, which in general, respond to a pharmacologic dose of pyridoxine (vitamin B6). Alpha - aminoadipic semialdehyde dehydrogenase (antiquin) deficiency is the underlying defect. Piperideine-6- Carboxylate (P6C) is the cyclic isomer of alpha aminoadipic semialdehyde (AASA) and the equilibrium between P6C and Alpha aminoadipic semialdehyde is pH dependent. Folinic responsive seizures and PDS are allelic, and caused by mutations in the ALDH7A1 gene. Biochemical testing should be done prior to gene sequencing, and can be done regardless of pyridoxine therapy.
Special Instructions
This assay currently is not available in New York state.
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 | 24 hours (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 as soon as possible after collection.
Causes for Rejection
Bloody CSF; received thawed