J Korean Child Neurol Soc.  2004 May;12(1):43-49.

Large Scale Single Deletion of Mitochondrial DNA in Chronic Progressive External Ophthalmoplegia

• Koh KN
• Park SY
• Hwang H
• Chae JH
• Choi JE
• Kim KJ
• Hwang YS

Abstract

PURPOSE: Chronic progressive external ophtahlmoplegia(CPEO) is a common phenotype of mitochondrial myopathy. CPEO has wide clinical spectrum with variable severity and can be divided into 3 groups; Kearns-Sayre syndrome, ophthalmoplegia plus and isolated CPEO. Single large-scale deletion, multiple deletions, point mutation of muscle mitochondrial DNA(mtDNA) and nuclear gene defect are associated with CPEO. We reviewed two cases of CPEO associated with the gene defect of mtDNA.
METHODS
mtDNA was extracted from muscle biopsy tissue and blood leukocytes. We carried out polymerase chain reaction(PCR), restriction fragment length polymorphism (RFLP) assay and automated sequencing of the mtDNA.
RESULTS
Case 1 presented with progressive external ophthalmoplegia, short stature, hypothyroidism and sensorineural hearing loss. A novel 7.6 kb-deletion was found in muscle and leukocyte mtDNA. Case 2 presented with isolated CPEO. A novel 6.2 kb- deletion was found in muscle mtDNA.
CONCLUSION
We detected novel single large-scale deletion of mtDNA in 2 cases of CPEO with various clinical manifestations in our population. We have to investigate multi-organ involvement with regular follow-up for patients who present with progressive ophthalmoplegia

Keyword

CPEO; Mitochondria; mtDNA; Deletion

MeSH Terms

Biopsy
DNA, Mitochondrial*
Follow-Up Studies
Hearing Loss, Sensorineural
Humans
Hypothyroidism
Kearns-Sayre Syndrome
Leukocytes
Mitochondria
Mitochondrial Myopathies
Ophthalmoplegia
Ophthalmoplegia, Chronic Progressive External*
Phenotype
Point Mutation
Polymorphism, Restriction Fragment Length
DNA, Mitochondrial