Alpha Aminoadipic Semialdehyde (Urine)


Test Details
TEST CODE MET20
TEST METHODOLOGY LC/MS/MS
TAT (TURNAROUND TIME) 10 - 14 days
CPT CODE 82017
PRICE $195

Clinical Information
Clinical Significance Urine Alpha aminoadipic semialdehyde (MET20) is useful for diagnosing pyridoxine-dependent seizures (PDS) and folinic acid-responsive seizures (FRS). Elevation of alpha aminoadipic semialdehyde can also occur in molybdenum cofactor deficiency. Urine Alpha aminoadipic semialdehyde (MET20) 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). CLINICAL 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. P6P reacts with pyridoxal 5\'-phosphate and leads to a deficiency of this cofactor. 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.
Relevant Diseases
  • Pyridoxine-Dependent Epilepsy

Specimen Information
Acceptable Sample Types
  • Urine
Sample Preparation: Collect 1 milliliter urine (random) and freeze at -20°Celsius. Store frozen at –20°Celsius and ship frozen. Preferred volume: 1.0 milliliter, minimum volume: 0.5 milliliter
Shipping Condition: Ship samples priority overnight on 3-4 lbs of dry ice. Sample must arrive in our lab Monday - Saturday. We do NOT accept Sunday or holiday deliveries.


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