RFC4: Myopathy with Aggregates & Nuclear pathology (MRMNS)
|
Aggregates Fiber types Myopathy Nuclei |
12 year old female
Genetics
RFC4 mutations L289R; c.996+4dup splice
Clinical
Weakness & Respiratory failure
Course: Slowly Progressive
Chronic myopathy
Muscle fiber size: Varied
Perimysial connective tissue: Replaced by fat
Endomysial connective tissue: Increased between muscle fibers
 H& E stain |
 H& E stain |
Aggregates
Nuclei: Large & Irregular
Size: Varied
 H& E stain |
Myonuclei
 Congo red stain |
 Congo red stain |
 Emerin stain |
Patient (Above): Myonuclei are Large & Irregular shaped
Control (Below): Myonuclei are Smaller
 Emerin stain |
Cytoplasmic Aggregate
 Gomori trichrome stain |
 VvG stain |
Shapes: Varied
 VvG stain |
Cytoplasmic Aggregates: Stain for desmin
 Desmin stain |
Cytoplasmic Aggregates: Smudged internal architecture
 NADH stain |
Internal architecture, Other fibers: Irregular
 NADH stain |
 AMPDA stain |
 AMPDA stain |
Cytoplasmic granules: Acid phosphatase stained
 Acid phosphatase stain |
Type I muscle fiber prodominance
 ATPase pH 4.3 stain |
Return to Neuromuscular Home Page
4/11/2025