Table 2.
Histological, ultrastructural and protein studies in patients’ muscle biopsies.
| Patient | Muscle biopsy | Biopsy (age range at biopsy) | MGT | NADH | IF RYR1/DHPR | IF αBcryst/Desm/Myot | Electron microscopy | Western Blot (% residual expression) |
|---|---|---|---|---|---|---|---|---|
| 1 | Biceps brachii | Central Core Myopathy (30–40 y) | Reddish purple granular material deposition |
Mini cores with irregular areas, without clear borders and round/ovoidal shape Mouth-eaten fibers, myofibrillar disruption |
Positive signals in core areas with widespread deposits of RYR1 and DHPR | Myofibrillar aggregates or thickening, that in some fibers show a core-like deposition | Some small areas of sarcomeric disorganization characterized by thickening of z-line |
RYR1: 28.49 ± 0.43 DHPR: 27.03 ± 3.18 |
| 2 | Biceps brachii |
Central Core Myopathy (50–60 y) |
Very low deposition of reddish-purple granular material | In most fibers presence of irregular core areas without clear borders and round/ovoidal shape | Positive signals in core areas with different intensity and distribution | Widespread myofibrillar deposits |
Areas of sarcomeric disorganization with abundant electrodense longitudinally smeared material and thickened short Z-line fragments. Multiple core areas may be present within the same fiber |
RYR1: 107.24 ± 4.36 DHPR: 46.88 ± 12.5 |
| 3 | Biceps brachii | Central Core Myopathy (<10 y) | Presence of reddish-purple granular material deposition inside and outside core areas | Presence of extensive and more regular core areas without clear borders | Positive signals in all core areas with more evident aggregates of RYR1 and DHPR | More evident myofibrillar aggregates or thickening, that in some fibers show a core-like deposition | Large core areas, sometimes showing irregular network of myofilaments with mild Z-line thickening and fragmentation in some fibers |
RYR1: 5.56 ± 0.38 DHPR:16.87 ± 9.2 |
| 4 | Quadriceps |
Fiber Type Disproportion (<10 y) |
Presence of mild and small reddish-purple deposition in few core areas |
Fibers with core-like areas without clear borders Some fibers with “targetoid” appearance |
Positive signals in core areas with different intensity and distribution Some fibers with accumulations of DHPR | Myofibrillar aggregates in some fibers | Core areas of variable size, irregular network of myofilaments and Z-line thickening |
RYR1: 51.34 ± 1.4 DHPR: 60.97 ± 5.52 |