Table 1.
Clinical and molecular genetic characteristics of our patient cohort
| Patient | Sex | Age | Age at onset of disease | Symptoms | MtDNA deletion size (bp) | MtDNA deletion breakpoints |
|---|---|---|---|---|---|---|
| 1 | F | 58 | 37 | CPEO, EI, fatigue | 3693 | nt.9756-nt.13449 |
| 2 | M | 46 | 28 | CPEO, EI, fatigue, GI problems | 4978 | nt.8469-nt.13447 |
| 3 | M | 39 | 16 | CPEO, EI, fatigue, GI problems | 4113 | nt.11262-nt.15375 |
| 4 | M | 59 | 10 | CPEO, EI, fatigue, ptosis | 4978 | nt.8469-nt.13447 |
| 5 | M | 45 | 29 | CPEO, EI, fatigue, ptosis | 7595 | nt.7845-nt.15440 |
| 6 | M | 35 | 33 | CPEO, EI, fatigue, GI problems | 8039 | nt.7637-nt.15676 |
| 7 | M | 31 | 16 | CPEO, EI, fatigue, SVT | 4978 | nt.8469-nt.13447 |
| 8 | F | 34 | 9 | CPEO, ptosis, mild dysphagia | 5340 | nt.6714-nt.12054 |
All patients displayed symptoms of myopathy, with CPEO and either ptosis or exercise intolerance (EI). All patients harboured a sporadically occurring single, large-scale mtDNA deletion, with precise mapping of the mtDNA deletion breakpoint showing that three patients (Patients 2, 4 and 7) had the 4977 bp common mtDNA deletion.
SVT, supraventricular tachycardia; GI, gastrointestinal tract.