Characterization of a 5025 base pair mitochondrial DNA deletion in Kearns-Sayre syndrome

• Published in: Biochimica et biophysica acta Vol. 1271; no. 2; pp. 363 - 368
• Main Authors: Vázquez-Acevedo, Miriam, Coria, Roberto, González-Astiazarán, Adalberto, Medina-Crespo, Violeta, Ridaura-Sanz, Cecilia, González-Halphen, Diego
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 09.06.1995
• Subjects: Adolescent; Base Composition; Base Sequence; Deletion; DNA, Mitochondrial - chemistry; DNA, Mitochondrial - genetics; Heteroplasm; Humans; Kearns-Sayre syndrome; Kearns-Sayre Syndrome - genetics; Male; Molecular Sequence Data; Mutation; Recombination; KSS, Kearns-Sayre syndrome; Recombination; CPEO, chronic progressive external ophthalmoplegia; BNE, Blue Native electrophoresis; Heteroplasm; Deletion; PCR, polymerase chain reaction; mtDNA, mitochondrial DNA; Mutation; Kearns-Sayre syndrome
• ISSN: 0925-4439; 0006-3002; 1879-260X
• DOI: 10.1016/0925-4439(95)00062-9

We characterized a mitochondrial DNA deletion in a patient with Kearns-Sayre syndrome. Southern blot hybridization showed that 86 to 93% of the mitochondrial genome harbored a 5.0 kb deletion. The percentage of affected genomes is higher than in previously described cases. Direct sequencing of the breakpoint region revealed that the deletion extended 5025 by from nt 10050 in the tRNA Gly gene to nt 15 076 in the cytochrome b gene, thus 30% of the total mitochondrial genome was lost by this deletion. A pair of extremely short mirror sequences flanking the mitochondrial DNA breakpoints were identified. These flanking sequences differ from previously published consensus ‘hot-spots’, known to give rise to deletions in human mitochondrial DNA.