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Updated: Jul 7, 2026

Genotyping Single Nucleotide Polymorphisms in the Mitochondrial Genome by Pyrosequencing
Published on: February 10, 2023
[PCR-based detection of heteroplasmic deleted mitochondrial DNA in Kearns-Sayre syndrome]
A Ramírez-Miranda1, A Navas-Pérez, L Gurria-Quintana
1Instituto de Oftalmología Conde de Valenciana, México DF, Mexico. arturorammir@gmail.com
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.

