Mitochondrial DNA deletion and duplication in Kearns–Sayre Syndrome (KSS) with initial presentation as Pearson Marrow‐Pancreas Syndrome (PMPS): Two case reports in Barranquilla, Colombia
Kearns–Sayre Syndrome (KSS) and Pearson Marrow‐Pancreas Syndrome (PMPS) are among the classic phenotypes caused by mitochondrial DNA (mtDNA) deletions. KSS is a rare mitochondrial disease defined by a classic triad of progressive external ophthalmoplegia, atypical pigmentary retinopathy, and onset before 20 years. PMPS presents in the first year of life with bone marrow failure and exocrine pancreatic dysfunction, and can evolve into KSS later in life. Even though an mtDNA deletion is the most frequent mutation in KSS and PMPS, cases of duplications and molecular rearrangements have also been described. In Colombia, few case reports of KSS and PMPS have been published in indexed journals or have been registered in scientific events.