Retinal Kearns-Sayre syndrome

Kearns-Sayre syndrome [17] A multisystem disorder characterized by the invariant triad onset before age 20 years, PEO, pigmentary retinal degeneration plus at least one of the following complete heart block, cerebrospinal fluid protein above 100 mg/dl, cerebellar ataxia. Large-scale heteroplasmic mitochondrial DNA deletions are frequently detected in skeletal muscle (rarely in other tissues). 

Large mtDNA deletions account for most cases of ocular myopathy and Pearson s marrow/pancreas syndrome. Ocular myopathy patients can exhibit a variety of clinical symptoms, from mild chronic progressive external ophthalmoplegia (CPEO) to Kearns-Sayre Syndrome (KSS). These diseases are characterized by an early onset of ophthalmoplegia, atypical retinitis pigmentosa, mitochondrial myopathy, and usually cerebellar syndrome and cardiac conduction abnormalities. More than 120 different mtDNA deletions have been identified from patients tissues. Partial duplications of mtDNA have been detected in ocular myopathy and Pearson s syndrome, however, duplications are much rarer than spontaneous deletions in patients with these conditions. Exactly how partial mtDNA duplications arise is unknown. 

KSS (Kearns-Sayre syndrome) CPEO plus retinal degeneration, cardiomyopathy, hearing loss, diabetes, renal failure. 

Kearns-Sayre syndrome Onset before 20 years of age, characterized by opthalmoplegia, atypical retinitis pigmentosa, mitochondrial myopathy, and one of the following cardiac conduction defect, cerebellar syndrome, or elevated CSF proteins. Deletion of contiguous segments of tRNA and OXPHOS polypeptides, or duplication mutations consisting of tandemly arranged normal mtDNA and an mtDNA with a deletion mutation. 

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