A Review on: Kearns-Sayre Syndrome (KSS)

Kearns-Sayre Syndrome (KSS) is a rare mitochondrial disorder characterized by progressive external ophthalmoplegia (PEO), pigmentary retinopathy, and cardiac conduction defects, typically presenting before the age of 20. It results from large-scale deletions or mutations in mitochondrial DNA (mtDNA), leading to impaired oxidative phosphorylation and decreased ATP production, especially in high-energy-demand tissues such as the eyes, heart, brain, and muscles. KSS follows a non-Mendelian, usually sporadic pattern of inheritance due to the unique properties of mtDNA. Patients often experience ptosis, muscle weakness, hearing loss, cerebellar ataxia, short stature, endocrine dysfunctions, and cognitive decline. Diagnosis is based on clinical presentation, supported by genetic testing, muscle biopsy, and imaging studies. Although there is no cure, treatment is supportive, including pacemaker implantation for cardiac issues, ptosis surgery, hormone replacement, and supplements like coenzyme Q10 and carnitine. KSS can overlap with other mitochondrial syndromes, including Pearson syndrome and progressive external ophthalmoplegia as isolated presentations. Early diagnosis and multidisciplinary management are critical for improving quality of life and minimizing complications.