Comparison of clinical characteristics, imaging, and muscle biopsy findings between patients with LMNA-CMD, JIIM, and our case.
| Characteristic | Our Patient’s Presentation | Infantile-onset LMNA-associated Muscular Dystrophy2,3,7,8 | JIIM1,9,10 |
|---|---|---|---|
| Proximal muscle weakness | + | + | + |
| Neck extensors involvement | − | + | − |
| Neck flexors involvement | − | + | +/− |
| Contractures | + | + | +/− 1 |
| Muscle edema | − | − | + |
| Skin disease | − | − | +/− |
| Skin ulceration | − | − | +/− |
| CK levels | 738–2700 IU/l | Levels to 2878 IU/l reported7,9. | Levels can vary from mild/moderate increase to high. |
| Histopathological analysis of muscle biopsy2 | See text body. | Variable pathology; dystrophic to nonspecific myopathic; often focal; whorled fibers, rounded atrophic fibers; prominent interstitial inflammation in some cases. | Diagnostic features: perifascicular atrophy, capillary pathology including complement deposition and capillary dropout, predominantly interstitial inflammation CD4/CD20++; electron microscopy tubuloreticular endothelial inclusions. |
| Muscle MRI | Loss of muscle bulk with relative sparing of rectus femoris, gracilis, sartorius, semimembranosus, and semitendinosus muscles. No muscle edema, fascial involvement, or subcutaneous inflammation. | Often diffuse involvement of thigh muscles with relative sparing of sartorius, gracilis, and rectus femoris. Diffuse or selective muscle involvement of vastus lateralis, vastus intermedius, and vastus medialis have also been described. | Diffuse or patchy muscle involvement. Muscle edema, myofascial, and subcutaneous tissue involvement. Loss of muscle bulk if myopathy with wasting. |
| Cardiac and respiratory involvement | No. | Life-threatening cardiac arrhythmias. Progressive restrictive respiratory failure. | Myocardial inflammation, dilated cardiomyopathy. Left ventricular diastolic dysfunction, often subclinical. Cardiac systolic dysfunction. ILD. |
LMNA-CMD: LMNA-associated congenital muscular dystrophy; JIIM: juvenile idiopathic inflammatory myopathy; CK: creatine kinase; MRI: magnetic resonance imaging; ILD: interstitial lung disease.