In men with Brody disease, nemaline myopathy type 6 (NEM6) and myotonic dystrophy type 2 a lower peak relaxation rate was identified. On the counter side, the same results were obtained in women with NEM6 and McArdle disease. TMS yielded different results distinguishing symptomatic controls from myopathic patients. This evidence concerns the gene KBTBD13 and myotonic dystrophy type 2.