Late-onset cerebellar ataxia in an adult with a novel mutation in the CLN5 gene

Abstract

Neuronal ceroid lipofuscinosis (NCL) is a neurodegenerative disorder which mostly presents in early life and is associated with a premature death. Here, we report a 50-year-old Saudi male who presented with cerebellar ataxia and whole exome sequencing identified a previously undescribed, homozygous mutation in the CLN5 gene (c.562T>C; p.Phe188Leu). This mutation was predicted to be pathogenic based on bioinformatics tools scoring; PolyPhen-2 (1) and SIFT (0.0). He did not have a visual impairment, cortical atrophy or cognitive decline, which were reported in previous adult cases associated with CLN5 mutation. This case, therefore, further expands the molecular and clinical phenotype associated with CLN5 mutation. It also highlights the role of next-generation sequencing analysis in providing early insights and diagnosis of rare hereditary disorders.