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HelpTest Code LAB2771 Alpha-aminoadipic semi-aldehyde
Clinical System Name
Alpha-aminoadipic semi-aldehyde
Synonyms
Piperideine-6-carboxylic acid (P6C)
AASA
Sample Requirements
Specimen: Whole Blood
Container(s): Dark Green/Sodium Heparin or Lt. Green/Lithium Heparin Tube
Preferred Vol: 1.0 mL
Minimum Vol: 0.5 mL
Note: Serum is acceptable but not preferred.
Processing Instructions
Reject due to: If sample is not spun and frozen within 1 hour of collection. 48 hr storage at -20 C is acceptable
Spin: Y
Aliquot:Y
Temp: -70 C
Storage location: -70 C freezer
Off-site collection: Plasma must be frozen at -70 C within 1 hour of collection. Ship on dry ice.
Stability
| Temperature | Time |
|---|---|
| Room temp | ≤1 Hr |
| Refrigerated | ≤1 Hr |
| Frozen (-700C) | 6 months |
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | W | 2-8 d |
Contact the Biochemical Genetics Lab for requests outside of stated availability (206)987-2216.
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Biochemical Genetics
Phone Number: 206-987-2216
CPT Codes
82542
Methodology
Method: Liquid chromatography-tandem mass spectrometry
Analytical Volume: 0.25 mL
Limitations:
Reference Range
| Age | <1 month | > 1 month |
| AASA (mcmol/L) | <0.4 | <0.3 |
| P6C (mcmol/L) | <0.8 | <0.5 |
Description
This test is used to diagnose pyridoxine-dependent seizures (PDS)
Clinical Utility
This test determines α-AASA and P6C concentration in plasma and serum for diagnosis of pyridoxine dependent seizures (PDS) and folinic acid-responsive seizures (FRS). Pyridoxine dependent seizures is a genetic disorder characterized by seizures in neonates or infants up to 3 years of age, which respond to a pharmacologic dose of pyridoxine (vitamin B6). Alpha-aminoadipic semialdehyde dehydrogenase (antiquin) deficiency is the underlying defect. 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.
Requisition
Biochemical Genetics Requisition
On the requisition include clinical information needed for appropriate interpretation. (Age, gender, drug therapy, and family history)