Case report of DNAJB4-related myopathy in France

Myologists from the Paris region, including an expert from the Institute, report the case of a patient with an ultra-rare myopathy:

• the clinical picture combined a predominantly distal motor deficit in the upper limbs with acute respiratory failure.
• In addition to CPKEnzyme contenue dans les cellules musculaires, qui est libérée dans le sang en cas d’atteinte musculaire. levels more than ten times higher than normal, the forced vital capacity at baseline was greatly reduced, to around 20% of the theoretical value.
• histology was consistent with myofibrillar myopathy,
• and genetic testing performed using NGS and confirmed by qPCR revealed the presence of a pathogenic homozygous variant in the DNAJB4 gene in the form of a small deletion.

This case is phenotypically similar to other cases reported in the literature.

Homozygous DNAJB4 deletion revealing myopathy with acute respiratory failure. Chitimus DM, Adam C, Cauquil C et al. Rev Neurol (Paris). 2025 Aug