Dysferlin deficiency treated like refractory polymyositis

Area of Science:

• Neurology
• Pathology
• Genetics

Background:

• Polymyositis diagnosis relies on muscle biopsy showing necrosis, fibrosis, and inflammation with MHC class I expression.
• Late-onset limb-girdle muscular dystrophy (LGMD) presents overlapping clinical and pathological features.
• Accurate differentiation is essential for appropriate patient management and treatment.

Observation:

• A young woman with dysferlin deficiency was misdiagnosed with refractory polymyositis.
• She received incorrect treatment for polymyositis for five years.
• Standard pathological analysis of muscle biopsy in LGMD can mimic polymyositis.

Findings:

• Dysferlin deficiency, a form of LGMD, can present with muscle biopsy findings similar to polymyositis.
• Standard histological examination is insufficient to distinguish between these conditions.
• Immunofixation is a critical diagnostic test to identify dysferlin deficiency.

Implications:

• Misdiagnosis of polymyositis can lead to delayed or incorrect treatment for LGMD patients.
• Implementing immunofixation can prevent diagnostic errors in cases with suspected polymyositis.
• Improved diagnostic accuracy ensures timely and effective management of muscular dystrophies.