[PCR-based detection of heteroplasmic deleted mitochondrial DNA in Kearns-Sayre syndrome]. / Detección de deleciones en DNA mitocondrial heteroplásmico por medio de PCR EN el síndrome de Kearns-Sayre.

OBJECTIVE: To describe the clinical data and the results of molecular analyses of the mitochondrial DNA in a patient with Kearns-Sayre Syndrome. METHODS: Molecular analyses of mitochondrial DNA from the patient included PCR amplification of a region where the common Kearns- Sayre deletion is located and Genotype-Phenotype correlations are discussed. RESULTS: The affected patient showed ptosis, progressive external ophthalmoplegia, pigmentary changes in the peripheral retina and right bundle block. Molecular analysis disclosed a approximately 5 kb deletion in the mitochondrial DNA and some wild type mtDNA indicating heteroplasmy. CONCLUSIONS: Molecular analysis of mitochondrial DNA confirmed the clinical diagnosis of Kearns-Sayre syndrome. PCR provides a rapid method to identify the common 4997 bp deletion in Kearns-Sayre syndrome. In such cases, PCR diagnosis could avoid invasive methods such as muscle biopsy or spinal tap.