Distal myopathies – New genetic entities expand diagnostic challenge

MR/CT imaging of fatty degenerative change in lower leg muscles. Genes causing predominant involvement of anterior compartment muscles: tibialis anterior, extensor hallucis longus and extensor digitorum longus.

MR/CT imaging of fatty degenerative change in lower leg muscles. Genes causing predominant involvement of posterior compartment calf muscles: gastrocnemius medialis, gastrocnemius lateralis and soleus.

MR/CT imaging of fatty degenerative change in lower leg muscles. Genes causing involvement of both anterior, lateral and posterior compartment muscles are the C-terminal Filamin-C mutations causing myofibrillar myopathy and alphaB-crystallin, but also the established distal myopathies Welander disease and the MPD3 [58] without yet identified genes this pattern is common.

Flow chart algorithm for diagnostic purpose aiming at reducing the number of genes qualified for possible molecular genetic testing, using morphological data as the starting point. (adapted from Udd: 165th ENMC International Workshop: Distal myopathies) [60].

Flow chart algorithm for diagnostic purpose aiming at reducing the number of genes qualified for possible molecular genetic testing, using clinical data as the starting point. (adapted from Udd: 165th ENMC International Workshop: Distal myopathies) [60].