Table 3.
Myopathological findings in patients with DES, MYOT or ZASP subtype of myofibrillar myopathy.
| Mutated gene
|
|||
|---|---|---|---|
| DES | MYOT | ZASP | |
| Light microscopy | |||
| Number of studied patients | 12 | 20 | 3 |
| Variation of fiber size | 12 | 20 | 3 |
| Fibro-fatty tissue proliferation | 4 | 10 | 3 |
| Vesicular nuclei | 3 | 16 | 3 |
| Necrosis/phagocytosis | 3 | 13 | 2 |
| Inflammatory infiltrates | 1 | 6 | 1 |
| Nemaline-like bodies | 3 | 18 | 3 |
| Core-like lesions | 7 | 20 | 3 |
| Type I fiber predominance | 8 | 18 | 1 |
| Vacuoles | 11 | 17 | 3 |
| Non-hyaline amorphous inclusions | 11 | 10 | 3 |
| Hyaline dense inclusions | 4 | 20 | 3 |
| Spheroid inclusion bodies | 2 | 18 | 3 |
| Rubbed-out fibers | 11 | 6 | 0 |
| Electron microscopy | |||
| Number of studied patients | 9 | 17 | 4 |
| Granulofilamentous material | 9 | 8a | 1a |
| Z-line streaming | 6 | 17 | 4 |
| Tubulofilamentous inclusions | 1 | 14 | 2 |
| Filamentous bundles | 0 | 17 | 4 |
| Autophagic vacuoles | 7 | 17 | 1 |
Biopsied muscle in DES cases: D (n = 4); B (n = 4); AT (n = 1); G (n = 2); Q (n = 1); in MYOT cases: D (n = 6); B (n = 3); AT (n = 1); G (n = 3); Q (n = 6); Sol (n = 1); in ZASP cases: Q (n = 1); not indicated (n = 2), where D, deltoid; B, biceps brachii; AT, anterior tibialis; G, gastrocnemius; Q, quadriceps; Sol, soleus.
a
Granulofilamentous material in MYOT and ZASP cases was restricted to small foci in a few fibers.