The high degree of sequence similarity between Kelch repeats of KBTBD13, KLHL40, and KLHL41 suggests that they may share identical or closely related binding partners whose dysregulation leads to nemaline myopathy through a common final pathway and implicates a critical role for BTB-Kelch family members in the maintenance of sarcomeric integrity in skeletal muscle. This evidence concerns the gene KLHL40 and nemaline myopathy.