%0 Case Reports
%T Kearns-Sayre syndrome case. Novel 5,9 kb mtDNA deletion.
%A Grigalionienė K
%A Burnytė B
%A Balkelienė D
%A Ambrozaitytė L
%A Utkus A
%J Mol Genet Genomic Med
%V 11
%N 1
%D 01 2023
%M 36181358
%F 2.473
%R 10.1002/mgg3.2059
%X Kearns-Sayre syndrome (KSS) is a rare multisystem mitochondrial disorder characterized by onset before 20 years of age and a typical clinical triad: progressive external ophthalmoplegia, pigmentary retinopathy and cardiac conduction anomalies. In most cases KSS is caused by spontaneous heteroplasmic single large-scale mitochondrial DNA (mtDNA) deletions. Long-range polymerase chain reaction (LR-PCR), next generation sequencing (NGS) and multiplex ligation-dependent probe amplification (MLPA) are the most widely applied methods for the identification of mtDNA deletions. Here, we report the case of 20-year-old male who presented with classic Kearns-Sayre syndrome, confirmed by novel 5,9 kb mtDNA deletion.<BR>LR-PCR and MLPA methods were applied to identify the mitochondrial DNA deletion for the patient, but the results were conflicting. Molecular analysis using primer walking and Sanger sequencing identified a novel 5888 base pairs mtDNA deletion (NC_012920.1:m.6069_11956del) with CAAC nucleotides repeat sequence at the breakpoints.<BR>Our study enriched the mtDNA variation spectrum associated with KSS and demonstrated the importance of choosing relevant molecular genetic methods.