One sibling presented with sensory ataxic neuropathy, dysarthria, and ophthalmoparesis (SANDO), a phenotype previously associated with the POLG1 gene, highlighting the clinical overlap in autosomal PEO.
ANT1, TWINKLE and POLG genes affect mtDNA stability and are involved in autosomal dominant PEO, while mutations in POLG are responsible for numerous clinical presentations, including autosomal recessive PEO, sensory ataxic neuropathy, dysarthria and ophthalmoparesis (SANDO), spino-cerebellar ataxia and epilepsy (SCAE) or Alpers syndrome.
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.
The triad of sensory ataxic neuropathy, dysarthria, and ophthalmoparesis (SANDO) has been demonstrated in a small subset of patients with POLG1 mutations.
We aim to describe the longitudinal clinical features and the treatment response of three unrelated patients with neurodegenerative parkinsonism, preceded by PEO and SANDO syndromes, who harbor POLG1 mutations, including two novel mutations.
This is the case in several syndromes caused by impaired mtDNA maintenance, such as Sensory Ataxic Neuropathy, Dysarthria and Ophthalmoplegia (SANDO) due to recessive mutations in the POLG gene, which encodes the catalytic subunit of mtDNA polymerase (DNA polymerase gamma), or Mitochondrial Neuro-Gastro-Intestinal Encephalomyopathy (MNGIE), due to recessive mutations in the TYMP gene, which encodes thymidine phosphorylase.
We aim to describe the longitudinal clinical features and the treatment response of three unrelated patients with neurodegenerative parkinsonism, preceded by PEO and SANDO syndromes, who harbor POLG1 mutations, including two novel mutations.