For the investigation of creatine biosynthesis disorders by measurement of creatine and its precursor guanidinoacetate (GAA) in blood and urine.Three disorders of creatine biosynthesis have been described – Guanidinoacetate methyltransferase (GAMT) deficiency, arginine:glycine amidinotransferase (AGAT) deficiency and x-linked creatine transporter defect (SLC6A8).
Presentation of the three creatine synthesis disorders is neurological with psychomotor retardation, developmental delay, speech delay and epilepsy being the most common features.
Contact Biochemical Genetics laboratory for further advice if required.
Tube
Plain Universal (urine) / Lithium Heparin (plasma)
ID
29939
Availability
Weekdays.
Additional Information
Urine is essential for the investigation of a creatine transporter defect.
Turn Around
30 days.
Send to
Specialist Laboratory Medicine
Centre for Laboratory Medicine
St James hospital
Beckett Street
Leeds
LS9 7TF
Contact
For further details please contact Leeds Pathology customer services: [email protected].
Collection Con
Minimum volume: 0.1 mL
Instructions for lab: On receipt of samples, urine samples should be frozen and lithium heparin blood samples should be spun down immediately, plasma separated and then frozen (urine/plasma must be frozen with 2 hours of collection). Please record the time the sample is frozen on the request card.
Send to Centre for Laboratory Medicine. If storage required (overnight or over the weekend) store in freezer (-20°C).
Please discuss with Biochemical Genetics lab prior to rejecting any samples.
Frequency
Once a month.
Sample REQ
For initial investigations both urine and plasma should ideally be sent. For monitoring of known GAMT or AGAT deficiency patients only a plasma sample is required. Please send samples ASAP to the lab.
Ref. Range Notes
Age related reference range supplied on the report as appropriate. Contact Biochemical Genetics laboratory for further advice if required.
Units
Urine: µmol/mmol creatinine. Plasma: µmol/L.