Histopathology of THOC2 splice-site arthrogryposis shows filamentous cytoplasmic inclusions

Following the description in 2021 of a family with X-linked arthrogryposis due to a mutationModification soudaine et transmissible du matériel génétique. Elle peut être spontanée ou induite par des agents dits » mutagènes » (radiations, produits toxiques,…). in the THOC2 gene, a French team reports :

• another family with the same mutation responsible for arthrogryposis.
• Muscle biopsy showed a wide variation in the size of muscle fibres, as well as the presence of cytoplasmic bodies in almost 1% of muscle fibres, consisting of filamentary material that was denser in the centre.
• on electron microscopy, some fibres showed sub-sarcolemmal disorganisation.

Muscular phenotype description of abnormal THOC2 splicing. Dubucs C, Rendu J, Michel-Calemard L et al. Neuromuscul Disord. 2023 Oct 5:S0960-8966(23)00735-6.