Most nemaline myopathy patients have mutations in the nebulin (NEB) or skeletal 
muscle alpha-actin (ACTA1) genes. Here we report for the first time three 
patients with severe nemaline myopathy and mutations of the ACTA1 stop codon: 
TAG>TAT (tyrosine), TAG>CAG (glutamine) and TAG>TGG (tryptophan). All three 
mutations will cause inclusion of an additional 47 amino acids, translated from 
the 3' UTR of the gene, into the mature actin protein. Western blotting of one 
patient's muscle demonstrated the presence of the larger protein, while 
expression of one of the other mutant proteins fused to EGFP in C2C12 cells 
demonstrated the formation of rod bodies.