Are mitochondrial DNA deletions causative in chronic progressive external ophthalmoplegia patients?

Genotypic and phenotypic changes in exhaustively grown cell lines from mitochondrial cytopathy patients

“…Total DNA was extracted as above from the muscle biopsy or myoblasts at various passage numbers, and 1-2 µg was digested with 10U of BamHI, electrophoresed on a 0.6% wt/vol agarose gel, transferred onto a nylon membrane (Hybond N+, Amersham), and hybridized as previously described. 23 The mtDNA probe was labeled with Digoxigenin (whole mt genome, DIG; Boehringer Mannheim), 23 or ␣ 32 P-dCTP (nt1581-nt5482; Amersham). The DIG-labeled bands were colorimetrically detected with nitroblue tetrazolium (NBT) and 5-bromo-4-chloro-3-indoyl phosphate (X-phosphate) for 1-3 h at RT.…”

“…DNA studies (Southern blot) revealed the presence of the mtDNA common deletion in a heteroplasmic manner. 23 Disease-Control Patients. Skeletal muscle biopsies (m. quadriceps femoris or m. vastus lateralis) were obtained from 9 control patients investigated for muscle pain, weakness, or fatigue, where muscle biopsy histology revealed either no abnormality or nonspecific type IIb fiber atrophy.…”