Kearns-Sayre syndrome

Kearns-Sayre syndrome is classed as a mitochondrial disease and is a clinical variant of external myopathic ophthalmo-plegia with pigment degeneration of the retina and cardiac conduction abnormalities. Mitochondrial diseases are characterised by disorders relating to oxidative phosphorylation, involvement of the muscles and multiple systems, and genotype/phenotype variability. They are usually caused by primary mutations in the mitochondrial DNA.

Furthermore, mutations in the nuclear DNA may cause a secondary instability of the mitochondrial genome. As a result, it may occur as sporadic, maternal or autosomal inheritance patterns. Familial cases generally show mitochondrial transmission with matrilineal (on the mother’s side) inheritance. The variability in the severity of symptoms…