Introduction: Leigh disease and Leigh-like syndrome are a heterogenous group of neurodegenerative disorders involving any level of the neuraxis and may present with a variety of clinical presentations, prominent among them is psychomotor regression. Despite the remarkable number of established disease genes and novel mutations being discovered, many cases of Leigh syndrome remain without a genetic diagnosis, indicating that there are still more disease genes to be identified. Case: Here we present a case of a two and a half-year-old girl who presented with delayed acquisition of developmental milestones with subsequent regression, ataxia, and dyskinesia. Her work-up showed raised blood lactate levels and lactate peak in MR spectroscopy. Mitochondria genome showed absence of mitochondrial DNA mutation, while whole exome sequence analysis revealed a novel dynein gene variant, p.A1577S. Her parents underwent genetic testing as well, and her father also had the same dynein mutation, however, is non-symptomatic. She had an older brother who initially presented with ophthalmoplegia and eventually developed psychomotor regression. He subsequently expired from respiratory failure after almost 2 years from initial presentation. Both siblings were diagnosed with Leigh syndrome. Conclusion The diagnosis of Leigh syndrome remains based on characteristic clinical and radiologic findings. However, a specific defect must be identified if reliable genetic counseling is to be provided.
Neurodegenerative Diseases|leigh Disease