Neuronal Ceroid Lipofuscinosis, Two-Enzyme Panel, Leukocytes

Casandra

Casandra Test Code MC82576Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID NCLWCPT Code 82657

Neuronal Ceroid Lipofuscinosis, Two-Enzyme Panel, Leukocytes

Clinical Use

Use

The test is essential for supporting the biochemical diagnosis of CLN1 and CLN2, which are two forms of neuronal ceroid lipofuscinoses (NCL). NCLs are a group of recessively inherited neurodegenerative disorders that involve lysosomal protein catabolism, characterized clinically by vision loss, seizures, developmental regression, and movement disorders. The specific forms CLN1 and CLN2 are caused by defects in palmitoyl-protein thioesterase 1 and tripeptidyl peptidase 1, respectively. This test is particularly useful for individuals with clinical signs suspicious for CLN1 or CLN2, providing initial enzymatic diagnostic screening. However, additional biochemical or molecular testing is necessary to confirm a diagnosis if an enzyme deficiency is detected.

Special Instructions

The test is intended for individuals aged 0 to 4 years who display symptoms consistent with neuronal ceroid lipofuscinosis. Collect and package specimens as close to shipping time as possible to optimize leukocyte isolation. Ship refrigerated specimens within 6 days of collection. Note: Patient's age and reason for testing are required.

Limitations

The test is not designed for carrier detection and may not reliably detect carrier status. Individuals with pseudodeficiency alleles can show reduced enzyme activity, and those receiving enzyme replacement therapy might exhibit normal enzyme levels. Additional confirmatory biochemical or molecular testing is required for definitive diagnosis.

Test Details

New York Approved