Table 1.
Subjects | Gender | Age of onset | Age at biopsy | Phenotype | Skeletal muscle histochemistry | Multiple mtDNA deletions | Genotype |
---|---|---|---|---|---|---|---|
Patients with autosomal dominant mutations | |||||||
P 1 | f | 36 | 46 | CPEO | 30–40% COX-ve; 3–5% RRF | Southern blot, LRPCR | p.(Phe961Ser) POLG |
P 2 | f | n.k. | 39 | CPEO | 9% COX-ve; increased number of RRF | LRPCR, qPCR | p.(Tyr955Cys) POLG |
P 3 | m | Since youth | 52 | CPEO, hypoacusis, neuropathy, muscle weakness, exercise intolerance | 10% COX-ve; 2% RRF | Southern blot, LRPCR | p.(Lys319Glu) TWNK |
P 4 | f | 57 | 60 | CPEO, deafness | 8–10% COX-ve; 1% RRF | LRPCR | p.(Met455Thr) TWNK |
P 5 | f | 48 | 58 | CPEO | slightly increased number of COX-ve; 1% RRF | LRPCR | p.(Arg354Pro) TWNK |
P 6 a,b | m | n.k. | 47 | CPEO, bilateral ptosis | 20% COX-ve; 8% RRF | LRPCR | p.(Asp104Gly) SLC25A4 |
P7c | f | n.a | 31 | CPEO | 10% COX-ve, 1% RRF | LRPCR | p.(Arg374Gln) TWNK |
Patients with autosomal recessive mutations | |||||||
P 8 d | m | n.k. | 36 | Severe CPEO, ptosis, proximal muscle weakness, facial weakness, scapulae winging, low BMI, hypogonadism and osteoporosis | 45% COX-ve; 15% RRF | LRPCR | p.(Thr144Ile) and p.(Gly273Ser) RRM2B |
P 9 a,c, e | f | n.k. | 43 | Severe CPEO, asymmetrical ptosis, proximal and distal muscle weakness, ataxia, SNHL, facial weakness, low BMI, leukoencephalopathy and depression | 22% COX-ve; 8% RRF | LRPCR | p.(Arg186Gly) and p.(Thr218Ile) RRM2B |
P 10 | m | Since youth | 54 | CPEO, dementia, neuropathy | 20% COX-ve; 10% RRF | Southern blot, LRPCR | p.(Gly848Sser) and p.(Ala899Thr) POLG |
P 11 | m | 23 | 25 | Stroke-like episode, ataxia, proximal muscle weakness, dysphagia | 5–7% COX-ve; no RRF | LRPCR | p.(Gly848Ser) and p.(Arg627Gln) POLG |
P 12 | m | n.k. | 43 | CPEO, muscle weakness | 22% COX-ve; 1% RRF; | Southern blot, LGPCR | homozygous p.(Trp748Ser) POLG |
P 13f | f | 23 | 37 | CPEO, neuropathy, dysarthria, seizures | <1% COX-ve; <1% RRF | LRPCR | p.(Arg467Thr) and p.(Trp748Ser) POLG |
P 14 | f | 67 | 77 | CPEO, neuropathy | 10% COX-ve; 1% RRF | LRPCR | p.(Arg467Thr) and p.(Thr919Leu) POLG |
P 15 | f | 26 | 36 | CPEO | 17%, COX-ve, 9% RRF | Southern blot, LRPCR | homozygous p.(Gly426Ser) POLG |
P 16 | m | 25 | 80 | CPEO | 20% COX-ve, 4% RRF | LRPCR | p.(Thr251Ile) and p.(Arg467Thr) POLG |
Key: y = years old; CPEO = chronic progressive external ophthalmoplegia; SNHL = Sensorineural hearing loss; BMI = body mass index; RRF = ragged red fibres; COX-ve = COX-deficient fibres; LRPCR = long range PCR; n.k = not known. a-f indicate previously published cases. a: Rocha et al. (2015), b: Deschauer et al. (2015), c: Vincent et al. (2018), d: Gorman et al. (2015), e: Pitceathly et al. (2012), f: Hanisch et al. (2015).