Ryanodine receptor 1 ( RYR1 ) mutations in two patients with tubular aggregate myopathy

Figures

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  FIGURE 1. Histochemical staining of muscle biopsies. Muscle biopsies from patient 1 (a–c) and patient 2 (d–f) show a muscle fibre with tubular aggregates which appear basophilic on haematoxylin and eosin (a, d), stain bright red with the modified Gomori trichrome (b, e) and dark blue with NADH‐TR (c, f). Muscle biopsies from patient 1 (g, i) and patient 2 (h, j) show several muscle fibres with multiple tubular aggregates strongly reactive in NADH‐TR staining (g and h) and negative to SDH reaction (i and j). Bar: 20 μm (a–f); bar: 50 μm (g–j)

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  FIGURE 2. Characterization of tubular aggregates. NADH‐TR and immunofluorescence staining for SERCA1, RYR1 and STIM1 (a–h). Muscle biopsy from patient 1 (a–d) and patient 2 (e–h) were stained with NADH‐TR (a, e) and decorated with antibodies for SERCA1 (b–f), RYR1 (c, g) and STIM1 (d, h). Images were obtained with objective ×40. Bar: 20 μm. NADH‐TR and immunofluorescence staining for SERCA2. Muscle biopsies from patient 1 (i–j) and patient 2 (k–l). No signal for SERCA2 (j, l) was detected in tubular aggregates found in type 2 muscle fibres (I, K; NADH‐TR). Arrowheads point to type 1 muscle fibres. Images were obtained with objective ×20, scale bar: 20 μm. Transmission electron micrographs of muscle biopsy of patient 1 (m–n). Electron microscopy analysis of muscle fibres from patient 1 shows large tubular aggregates (m, n). In (n), the aggregate is composed of bundles of tubules running in various directions. N, nucleus; *, tubular aggregate. Bars: 500 nm (m), 200 nm (n)