Laboratory Testing

Laboratory diagnostics for CLN2 disease are well established and straightforward1

Pathogenic variants/mutations in the TPP1/CLN2 gene, which encodes the tripeptidyl-peptidase 1 (TPP1) enzyme, cause the disease.1

Diagnostic tests will either:

  • Two pathogenic variants in trans (from separate parental alleles) in the TPP1/CLN2 gene1
    • There are two commonly reported pathogenic variants associated with CLN2 disease: c.509-1G>C and c.622C>T (p.Arg208Ter), and at least one of these two mutations can be present in up to 80% of patients with CLN2 disease1,2


  • Deficient TPP1 enzyme activity1

Molecular testing of CLN2/TPP1 gene is included on many commercially available symptom-based (eg, epilepsy, ataxia) and disease-based (eg, NCL, LSD) panels.1

TPP1/CLN2 Molecular testing in presence of seizures and/or other clinical signs of CLN2 disease

An early diagnosis facilitates access to CLN2-specific management strategies that can positively impact quality of life for children and their families and enables the genetic counseling that is crucial to family planning.

BioMarin has partnered with Invitae to bring you the Behind the SeizureTM program—a no-charge epilepsy gene panel testing program to help you diagnose CLN2 disease early.

In as little as 2 weeks, an epilepsy gene panel test can bring you and your eligible patients closer to identifying if there is a genetic cause behind the seizure.

Visit to learn more and to order a test.

References: 1. Fietz M, AlSayed M, Burke D, et al. Diagnosis of neuronal ceroid lipofuscinosis type 2 (CLN2 disease): Expert recommendations for early detection and laboratory diagnosis. Mol Genet Metab. 2016;119:160-167. 2. Kousi M, Lehesjoki A-E, Mole SE. Update of the mutation spectrum and clinical correlations of over 360 mutations in eight genes that underlie the neuronal ceroid lipofuscinoses. Hum Mutat. 2012;33:42-63.