stop mutation

stop mutation

Any mutation that changes a codon that codes for an amino acid into a codon that codes for a ‘stop’. Stop codons are UAG (amber codon), UAA (ochre codon) and UGA (opal codon). The effect of a stop mutation is that a protein is shortened so that an abnormal form is produced. CYSTIC FIBROSIS, MUSCULAR DYSTROPY and other genetic disorders are caused by stop mutations. See also PTC124.