AbstractThis investigation was undertaken to find out whether the structural and biochemical changes seen in skeletal muscles in congenital nemaline myopathy (CNM) occurred also in nonmuscle cells. It was confirmed that nemaline bodies contain α‐actinin. The distribution of actin and α‐actinin in the examined nonmuscle cells was considered normal. The motility of the leucocytes and the fibroblasts was indistinguishable from that of those in normal controls. Slight changes in the peripheral nerve fibers of one patient were found, but these were not seen in another patient. The results indicate that congenital nemaline myopathy is not a generalized disorder but is restricted to skeletal m