Table 2.
Clinical and Molecular Features of the Patients Harboring Single mtDNA Deletion
| Patient | Sex | Clinical features | Age (years) | Characterization of mtDNA deletion
|
mtDNA content (mtDNA/B2M ratio)
|
% of mtDNA deletion by Southern blot and real-time qPCR
|
|||
|---|---|---|---|---|---|---|---|---|---|
| Size (kb) | Breakpoints | % of age matched mean | Southern blot | Real-time QPCR (ND4) | Real-time QPCR (ATP8) | ||||
| 11m | F | KSS | 33 | Common, 5 | (8469–8482):(13447–13460) | 129 | 51 | 60 | 65 |
| 12m | F | Atypical Pearson/multisystemic/KSS | 8 | 4.5 | 10559:14981 | 174 | 55 | 57 | 0 |
| 13b | M | Pearson/multisystemic | 0.8 | 2.3 | 12113:14421 | 152 | 90 | 86 | 0 |
| 14b | F | Multisystemic | 1.3 | 7.1 | 8536:15642 | 105 | 65 | 74 | 0 |
| 15m | F | KSS | 39 | Common, 5 | (8469–8482):(13447–13460) | 259 | 64 | 67 | 66 |
| 16b | M | Pearson/multisystemic | 1.2 | 5.2 | 10418:15570 | 173 | 80 | 84 | 0 |
| 17m | F | KSS | 79 | Common, 5 | (8469–8482):(13447–13460) | 95 | 27 | 24 | 29 |
| 18m | M | KSS | 20 | Common, 5 | (8469–8482):(13447–13460) | 181 | 88 | 90 | 90 |
| 19m | F | Atypical KSS (mild) | 40 | del-dupl, 3.1 | (8420–8424):(11498–11502) | 391 | 92 | 0 | 96 |
| 19b | F | KSS | 40 | Blood of 19 | (8420–8424):(11498–11502) | ND | 0 | 0 | 12 |
| 20m | F | KSS/ multisystemic | 40 | 7.7 | (6331–6341):(13994–14004) | 165 | 24 | 41 | 42 |
| 21m | F | KSS | 48 | 5 | (9256–9265):(13625–13634) | 152 | 23 | 43 | 23 |
| 22b | M | KSS/multisystemic | 9 | 7.7 | (6331–6341):(13995–14004) | 155 | 44 | 53 | 50 |
| 23b | M | KSS | 9 | 5 | (8469–8482):(13447–13460) | 240 | 53 | 61 | 63 |
| 24m | F | KSS | 25 | 4 | (10951–10957):(13989–13995) | 150 | 48 | 44 | 0 |
b, blood; m, muscle; KSS, Kearns Sayre Syndrome; ND, not done; mtDNA content, the ratio of mtDNA copy number to B2M gene copy number. Usually the results from the two non-deleted mtDNA probes (tRNA leuUUR and D-loop region) were consistent with each other (coefficient of variance <3%), the mean value of the two nondeleted regions was used to calculate the mtDNA content. Percentages of mtDNA deletion by real-time qPCR were calculated from the copy number of the deleted region (ND4 or ATP8 region depending on the region of deletion) and the copy number of the nondeleted region (mean of tRNA leuUUR and D-loop region) using the formula: [(copy number of nondeleted region − copy number of deleted region)/copy number of nondeleted region] × 100%. Percentage of mtDNA deletion by Southern blot was calculated as described in the legend of Fig 2A. The mtDNA content obtained from a pool of muscle DNA samples from 10∼20 age-matched individuals was used as age-matched mean.