Progressive External Ophthalmoplegia with Mitochondrial Dna Deletions, Autosomal Recessive 3, is also known as peob3. An important gene associated with Progressive External Ophthalmoplegia with Mitochondrial Dna Deletions, Autosomal Recessive 3 is TK2 (Thymidine Kinase 2). Affiliated tissues include skeletal muscle, and related phenotypes are ptosis and dysphagia