LAUSR

Kearns‐Sayre syndrome (KSS) is a rare multisystem mitochondrial disorder characterized by onset before 20 years of age and a typical clinical triad: progressive external ophthalmoplegia, pigmentary retinopathy and cardiac conduction anomalies. In most cases KSS is caused by spontaneous heteroplasmic single large‐scale mitochondrial DNA (mtDNA) deletions. Long‐range polymerase chain reaction (LR‐PCR), next generation sequencing (NGS) and multiplex ligation‐dependent probe amplification (MLPA) are the most widely applied methods for the identification of mtDNA deletions. Here, we report the case of 20‐year‐old male who presented with classic Kearns‐Sayre syndrome, confirmed by novel 5,9 kb mtDNA deletion.