Identification & Diagnosis

Laboratory Testing

Laboratory diagnostics for CLN2 disease are well established and straightforward1

CLN2 disease is caused by pathogenic variants/mutations in the tripeptidyl peptidase 1 (TPP1)/CLN2 gene and the resulting deficiency of the TPP1 enzyme.

Diagnostic tests will either show:

  • 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 89% of patients with CLN2 disease1,2

AND/OR

  • 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 genetic counseling that is crucial to family planning.

 

BioMarin has partnered with Invitae/Lacorp to bring you the Behind the Seizure® program—a no-cost epilepsy gene panel testing program to help health care providers diagnose CLN2 disease earlier.

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 Behind the Seizure 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.