Neuronal Ceroid Lipofuscinosis 1 (CLN1): Palmitoyl-Protein Thioesterase 1 Enzyme Analysis

This biochemical test is a quantitative measurement of palmitoyl-protein thioesterase 1 enzyme activity and can be used as a 1st tier test for patients with a clinical suspicion of Neuronal Ceroid Lipofuscinosis Type 1 (CLN1). Demonstration of deficient palmitoyl-protein thioesterase 1 enzyme activity is considered the gold standard to confirm a diagnosis of Neuronal Ceroid Lipofuscinosis Type 1 (CLN1).
In addition, this assay can be used to clarify molecular findings in the PPT1 gene and to monitor patients undergoing treatment.

Turnaround Time

2 weeks

CPT Code(s)

82657

Cost

$200

Enzymes

• Neuronal Ceroid Lipofuscinosis Type 1 (CLN1)

The neuronal ceroid lipofuscinoses (CLN) are a group of conditions that are inherited in an autosomal recessive pattern. CLN1 is characterized by progressive microcephaly, contractures, developmental delay, psychiatric symptoms, and neurological degeneration including seizures and ataxia. Retinal and macular degeneration leads to blindness by the age of 2 years with diminished or abolished ERG results. Age of onset varies with infantile, late-infantile, juvenile and adult-onset forms of the disease with younger ages of onset typically associated with a more rapid progression of symptoms. The intracellular accumulation of lipopigments results in a characteristic microscopic pattern called granular osmiophilic deposits (GROD).

This test can be used to confirm a suspected neuronal ceroid lipofuscinosis 1 (CLN1) diagnosis. Prenatal diagnosis and carrier testing via enzyme analysis are not available.

4-methylumbelliferyl substrate

Enzyme activity can be measured in leukocytes. For leukocytes, please send 5-10 ml of whole blood in a green top (sodium heparin) tube. See the link below for additional sample collection and handling instructions.

Whole blood samples (for leukocyte analysis) should be shipped at ambient temperature and must arrive at the laboratory the next day.