Adult-Onset Neuronal Ceroid Lipofuscinosis: CLN5 Variant Presenting as Focal Dystonia

This is the authors' abstract. We don't add key points for this paper.

Background: Neuronal ceroid lipofuscinosis (NCL) is a rare hereditary lysosomal storage disorder causing neuronal loss and progressive neurodegeneration. CLN variants cause varied phenotypic presentations. Case report: A 49-year-old male presented with late adult-onset progressive focal right lower limb dystonia. Imaging showed cerebellar atrophy, and genetic testing was positive for the CLN5 variant (c.826T > C; p.Phe276 Leu) with uncertain significance. Skin biopsy suggested NCL, which made us consider the variant pathogenic, leading to novel phenotypic presentation. Conclusion: Isolated focal dystonia has not been reported as an initial presentation in ANCL. Early genetic testing and periodic clinical assessments are advisable for better management and prognostication.