Mutations in the polymerase gamma-1 (POLG1) gene, encoding the catalytic subunit of the mtDNA-specific polymerase-γ, compromise the stability of mitochondrial DNA (mtDNA) and are responsible for numerous clinical presentations as autosomal dominant or recessive progressive external ophthalmoplegia (PEO), sensory ataxia, neuropathy, dysarthria and ophthalmoparesis (SANDO), spinocerebellar ataxia with epilepsy (SCAE) and Alpers syndrome.
Two siblings who developed fifth-decade-onset, concurrent progressive sensory ataxia, dysarthria, and ophthalmoparesis were found to be homozygous for the p.A467T mutation of the polymerase gamma (POLG) gene.
Sensory ataxic neuropathy with ophthalmoparesis (SANDO) caused by mutations in POLG gene, fulfilling the clinical triad of sensory ataxic neuropathy, dysarthria and/or dysphagia and ophthalmoparesis, has described in a few reports.
Sensory ataxia with neuropathy, dysarthria and ophthalmoparesis represent the clinical triad of SANDO, a specific mitochondrial phenotype first reported in 1997 in association with multiple mitochondrial DNA deletions and mutations in POLG1 or more rarely in the C10orf2 (twinkle-helicase) gene.
Sensory ataxia with neuropathy, dysarthria and ophthalmoparesis represent the clinical triad of SANDO, a specific mitochondrial phenotype first reported in 1997 in association with multiple mitochondrial DNA deletions and mutations in POLG1 or more rarely in the C10orf2 (twinkle-helicase) gene.
In general, patients (epsilon1267delG) were characterized by the onset of symptoms in early infancy, the presence of ophthalmoparesis, positive response to anticholinesterase treatment, and the benign natural course of the disease.