Neuronal Ceroid Lipofuscinosis Enzyme CLN2
Test Mnemonic
CLN2
CPT Codes
- 82657 - QTY (1)
Aliases
- Tripeptidylpeptidase
Performing Laboratory
Seattle Children's Hospital
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| N/A | Blood | See note | Ambient | Dried blood spots on filter paper (newborn screening card); 2 full circles |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 10 mL | Whole blood | ACD A or B (Yellow) | Ambient | Collect Monday - Thursday only. Specimen MUST arrive at Cleveland Clinic Laboratories before 3:00 p.m. on the day of collection. Do not spin. | |
| Two | Fibroblasts, cultured | T25 flask | Ambient | Two T-25 cultured fibroblast flasks | |
| 10 mL | Whole blood | Sodium heparin (Green) | Ambient | Collect Monday - Thursday only. Specimen MUST arrive at Cleveland Clinic Laboratories before 3:00 p.m. on the day of collection. Do not spin. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 6 mL | Whole blood |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | 24 hours |
| Frozen | Unacceptable |
| Refrigerated | 24 hours |
Days Performed
Varies (one day/week)
Turnaround Time
8 - 11 days
Methodology
| Name | Description |
|---|---|
| Fluorometric enzyme assay |
Reference Range
Special Info
For prenatal samples, maternal cell contamination testing is required. This must be ordered separately.
Clinical Info
Approximately 80% of patients with late infantile Neuronal Ceroid Lipofuscinosis (NCL) and 7% of patients with juvenile onset NCL have a deficiency of the lysosomal enzyme tripeptidyl peptidase 1 (TPP1). The disease is characterized by seizures, ataxia, myoclonus, psychomotor retardation, speech impairment, and vision loss.