In the last years the Kearns-Sayre-Syndrome has been defined with the typical trias of chronic external ophthalmoplegia, pigmentary retinal dystrophy and cardiac conduction defects. Today it is no longer believed to present an entity but a variant of the multiple plussymptoms of the ophthalmoplegia-plus group. In pediatrics the existence of this clinical disorder is not yet well acknowledged. The case of a 16-year-old patient is used as an example for the impressive clinical symptoms and the involvement of several organs in this clinical disorder. The combination with a Klinefelter-Syndrome has not previously been reported.