In our previous analysis of a desminopathy patient harboring a heterozygous single codon deletion (K240del; c.720_722delGAA), the analysis of respiratory chain enzymes in skeletal muscle homogenates also showed normal absolute and citrate synthase-normalized activities of complexes I and IV, but the analysis of single saponin-permeabilized skeletal muscle fibers finally depicted an in vivo inhibition of the complex I activity [67, 68]. Here, CS is linked to Desminopathy.