Muscle histology and histochemistry | Age at biopsy | SURF1 mutations | References |
COX deficit, remarkable lipid accumulation; subsarcolemmal increase of NADH activity | 5 years | A patient from Tirani’s SURF1-deficient complementary group with “atypical” LS | Tiranti et al,3 Tirani et al,43 Angelini et al42 and Munaro et al44 |
COX partial deficit, slight subsarcolemmal increase of SDH activity | Not reported | c.312del10insAT//c.567insCAGG | Sue et al9 and Van Coster et al45 |
Normal findings | 1.5 years | c.589insCTGC//c.702C>T | Poyau et al8 and Collombet et al46 |
COX deficit, subsarcolemmal increase of SDH and NADH activity | 4 years | c.312del10insAT//c.385G>A | Poyau et al8 and Collombet et al46 |
Normal findings (COX not assessed) | 3 years | c.312del10insAT//c.385G>A | Poyau et al8 and Collombet et al46 |
Variability in fibre size | 1.5 years | c.790delAG//c.820T>G | Teraoka et al7 |
COX deficit, lipid accumulation | 2 years | c.240+1G>T// c.531_534delAAAT | Bruno et al18 |
COX deficit slight variability of fibre diameter, several hypotrophic fibres | 5 years | Homozygous Q82X | Santoro et al10 |
Lipid accumulation, atrophy of type II fibres | 2.5 years | Homozygous c.790_791delAG | Rahman et al14 |
COX deficit | <2 years | c.312del10insAT//c.688C>T | Tay et al25 |
COX deficit, type I fibres atrophy | <2 years | Homozygous c.834G>A | Tay et al25 |
COX deficit, mild non-specific changes | <2 years | As above (siblings) | Tay et al25 |
COX deficit; several RRFs | <2 years | c.312del10insAT//c 822_824dupTACAT | Tay et al25 |
COX deficit | Not done | c.608T>C//c.675_692del18 | Sacconi et al20 |
Normal findings (including COX staining)* | 3 years | Homozygous c.867G>A | Van Riesen et al29 |
*Severe isolated COX deficiency detected by biochemical assay.
COX, cytochrome c oxidase; LS, Leigh syndrome; RRF, ragged red fibre; SDH, succinate dehydrogenase.