Early-onset motor polyneuropathy associated with a novel dominant NAGLU mutation

Introduction: NAGLU encodes N-acetyl-alpha-glucosaminidase, an enzyme that degrades heparan sulfate. Biallelic NAGLU mutations cause mucopolysaccharidosis IIIB, a severe childhood-onset neurodegenerative disease, while monoallelic mutations are associated to late-onset, dominantly inherited painful sensory neuropathy. However, to date, only one family with a dominant NAGLU-related neuropathy has been described. Case report: Here we describe a patient with early-onset motor polyneuropathy harboring a novel monoallelic NAGLU mutation. We found reduced NAGLU enzymatic activity thus corroborating the pathogenic role of the new variant. Discussion: Our report represents the second ever described case with dominant NAGLU-related neuropathy and the first case with early-onset motor symptoms. We underlie the importance of a thorough clinical description of this probably underestimated new clinical entity.