The ACTN3 gene is located on the long arm of chromosome 11q 13.2 as shown in Figure 1. In exon 16, a nonsense point mutation (C-T) alters a codon in the exon sequence from CGA to TGA. This changes the 578th amino acid from an Arginine to a premature stop codon (1).
1. North KN, Yang N, Wattanasirichaigoon D, Mills M, Easteal S, et al. (1999) A common nonsense mutation results in a-actinin-3 deficiency in the general population. Nature Genetics 21: 353–354.