Overview

Need for Early Diagnosis

Signs and symptoms of CLN2 disease go beyond epilepsy

Children are often diagnosed with epilepsy without a further workup for CLN2

  • Average age at diagnosis is 5 years, which is well into the neurodegenerative decline of CLN2 disease
  • Diagnosis of CLN2 disease can be delayed because1,2:
    • Initial presenting symptoms are nonspecific
    • CLN2 disease progression can be mistaken for side effects from anti-epileptic drugs.

Diagnosis of CLN2 disease is delayed an average of 2 years from first observed seizure at age 3.

CLN2 disease is often initially misdiagnosed, delaying accurate diagnosis

Early in the progression of CLN2 disease3,4:

  • Since seizures and myoclonus are the most prominent symptom, syndromes where myoclonus is common (eg, focal epilepsy; myoclonic epilepsy syndromes/myoclonic astatic epilepsies, like Doose syndrome, Dravet syndrome, Lennox-Gastaut syndrome; or other epilepsy syndromes) are often suspected

Later in the progression of CLN2 disease3:

  • As the disease progresses and psychomotor regression and functional loss become more prominent, other progressive pediatric brain disorders may be suspected (eg, inflammation/infections, tumors, mitochondrial disorders, and other lysosomal storage diseases, including other NCL types)

The differential diagnosis of CLN2 disease varies depending on the stage of disease progression.

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 Sep;119(1-2):160-7. doi: 10.1016/j.ymgme.2016.07.011.
  2. Williams RE, Adams HR, Blohm M, et al. Management Strategies for CLN2 Disease. Pediatr Neurol. 2017 Apr;69:102-112. doi: 10.1016/j.pediatrneurol.2017.01.034.
  3. Chang M, Cooper JD, Davidson BL, et al. CLN2. In: Mole S, Williams R, and Goebel H, eds. The neuronal ceroid lipofuscinoses (Batten Disease). 2nd ed. Oxford, United Kingdom: Oxford University Press; 2011:80-109.
  4. Pérez-Poyato MS, Marfa MP, Abizanda IF, et al. Late infantile neuronal ceroid lipofuscinosis: mutations in the CLN2 gene and clinical course in Spanish patients. J Child Neurol. 2013;28:470-478.
  5. Mole SE, Williams RE, and Goebel HH. Correlations between genotype, ultrastructural morphology and clinical phenotype in the neuronal ceroid lipofuscinoses. Neurogenetics. 2005;6:107-126.