Children with CLN2 disease

NCL disorders

CLN2 disease is one of the most common forms of NCL, also known as Batten disease1,2

There are 14 known types of neuronal ceroid lipofuscinosis (NCL)3

NCLs are a group of disorders that are the leading cause of dementia in children and adolescents.3

NCL disease nomenclature has been revised and reclassified to take into account the mutated gene and clinical onset4

NCL disease nomenclature

Classification and characteristics of NCLs4-6

Classification and characteristics of NCLs chart

*Known NCL diseases. Additional NCL genes remain to be identified.

SCAR7 is caused by TPP1 deficiency and may be a milder form of CLN2.

CLN2 and CLN3 are the most common forms of NCL worldwide.1

NCLs share a host of aetiological and clinical characteristics3

  • Severe and progressive neurodegeneration1
  • Debilitating triad of symptoms–seizures, dementia and vision loss3
  • Neuronal and retinal accumulation of ceroid lipofuscin7
    • NCLs feature distinct inclusion bodies, including granular, curvilinear, and fingerprint profiles8
    • In CLN2, the distinct curvilinear structure of ceroid lipofuscin is evident under microscopy8
  • Classic and atypical presentations with varying age of onset, symptoms and disease course based on type and phenotype3
NCL ultrastructural appearances

Ultrastructural appearances of different forms of NCL Haltia (2003)8

References:
1. Mole SE and Williams RE. Neuronal ceroid-lipofuscinoses. 2001 Oct 10 [Updated 2013 Aug 1]. In: Pagon RA, Adam MP, Ardinger HH, et al., eds. GeneReviews® [internet]. Seattle, WA: University of Washington; 1993-2016. 2. Haltia M. The neuronal ceroid-lipofuscinoses: from past to present. Biochimica et Biophysica Acta. 2006;1762:850-856. 3. Schulz A et al. NCL diseases – clinical perspectives. Biochimica et Biophysica Acta. 2013;1832:1801-1806. 4. Williams RE and Mole SE. New nomenclature and classification scheme for the neuronal ceroid lipofuscinoses. Neurology. 2012;79:183-191. 5. Kousi M et al. 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. 6. Fietz M 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 7. 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. 8. Haltia M. The neuronal ceroid-lipofuscinoses. J Neuropathol Exp Neurol. 2003; 62(1):1-13.