Unusual clinical presentation of a patient carrying a novel single 1.8 kb deletion of mitochondrial DNA.

ABSTRACT

Kearns-Sayre syndrome (KSS) is a mitochondrial encephalomyopathy characterized by progressive external ophthalmoplegia (PEO), pigmentary retinopathy and onset before the age of 20 years. Cerebellar ataxia, as well as short stature and increased protein content in the cerebrospinal fluid, are frequent additional symptoms. A single large mitochondrial (mt) DNA deletion of 4,977 bp is the most common molecular defect in KSS. Recently, different mutations have also been associated with incomplete, KSS-like phenotypes. We describe the unusual clinical presentation of a patient carrying a novel 1,814-bp deletion of mtDNA. In contrast with typical KSS, the clinical picture of this patient did not include either palpebral ptosis or PEO and was dominated by an ataxic syndrome.