ATYPICAL PRESENTATION OF LATE-ONSET TAY-SACHS DISEASE

Introduction: Late-onset Tay-Sachs disease (LOTS) is a lysosomal storage disease caused by deficient Beta-hexosaminidase A activity. Methods: We describe a 53-year-old woman who presented with adult-onset leg weakness, and whose initial diagnosis was progressive muscular atrophy without identifiable etiology. Development of cerebellar ataxia in mid-life prompted reassessment. Results: Beta-hexosaminidase A quantification assay demonstrated absence of the isozyme. Genetic testing identified compound heterozygous mutations in the HEXA gene, confirming the diagnosis of LOTS. Conclusions: The phenotypic spectrum of LOTS includes motor neuronopathy, ataxia, choreoathetosis, neuropathy, and psychiatric symptoms in various combinations. This patient highlights the emergence of different clinical features over many years and emphasizes the need to consider LOTS in the differential diagnosis of progressive muscular atrophy. Muscle Nerve49: 768-771, 2014