Used in the monitoring and diagnosis of cystinosis. Heterozygotes are phenotypically normal. Homozygotes usually present around 1 to 2 years old with polyuria, polydypsia, failure to thrive, rickets and Fanconi syndrome (generalised aminoaciduria with phoshaturia and glycosuria). They are treated with Cystagon which reduces lysosomal cystine accumulation and thereby preserves renal function.
Tube
Heparin (no gel preferred).
ID
30001
Availability
Weekdays.
Additional Information
Please note Cystinosis is NOT the same disease as cystinuria (a cause of renal stones).
Turn Around
28 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: 3 mL.
Instructions for lab: Do not separate. Store whole blood at room temperature. Must arrive at Centre for Laboratory Medicine SJUH within 24 hours of venepuncture to allow white cell preparation (takes 2.5 hours, not available at weekends).
Please discuss with Biochemical Genetics lab prior to rejecting any samples.
Frequency
Monthly.
Sample Req
Whole blood. Sample must be well mixed at venepuncture to prevent clots and received within 24 hrs of collection between Mon 9am to Fri 2pm. For monitoring a trough sample should be taken.
Ref. Range Notes
Normal: up to 0.5.
Heterozygotes: up to 1.0.
Cystinosis patients: usually greater than 2.0.
Units
nmol ½ cystine per mg protein.