Drug-refractory epilepsy due to a novel CLN5 mutation: A report of three patients from an Indian family.

Introduction: Neuronal Ceroid Lipofuscinosis (NCL) are a group of lysosomal storage disorders characterised by progressive neurodegeneration caused by an accumulation of ceroid lipopigment in lysosomes of neurons and other cell types. Adult-onset NCL (Kufs disease) differs from childhood forms by its later onset and preserved vision. Type A (Kufs A) presents as progressive myoclonus epilepsy (PME), while Type B (Kufs B) manifests as dementia with motor involvement. Both subtypes have distinct causative genes.

Methods: We have described 3 siblings with genetically confirmed novel pathogenic CLN5 subtype who presented with developmental regression, drug-refractory myoclonic epilepsy, and dementia (Kufs A).

Results: We have presented 3 siblings with adult onset NCL with Kufs A (not Kufs B) phenotype, which has been rarely documented.

Conclusion: Genotypic-phenotypic variations are increasingly being reported for NCL. We have described three patients from a family with CLN5 subtype who had prominent drug refractory myoclonic epilepsy, which is extremely rare.