A mitochondrial protein (684 aa) with structural similarity to various helicases. The protein colocalizes with mtDNA and the unusual localization pattern is said to be reminiscent of twinkling stars; expression is relatively high in skeletal muscle and pancreas. A splice variant lacks residues 579–684 but localizes in a similar way and was christened twinky. Mutations are associated with infantile-onset spinocerebellar ataxia and mutations in the same open reading frame are also associated with autosomal dominant progressive external ophthalmoplegia (PEOA3), sensory ataxia neuropathy, dysarthria, and ophthalmoparesis (SANDO) and some cases of autosomal recessive mitochondrial DNA deletion syndrome of the hepatocellular type.
Subjects: Medicine and Health.