Nonsense mutation introduces premature termination codon UAA, UAG, or UGA within open reading frame by single base substitution changing sense codon to stop. During elongation, release factor eRF1 recognizes stop codon leading to premature polypeptide release producing truncated protein often lacking critical domains. Transcripts containing early stop trigger nonsense-mediated mRNA decay reducing protein level. Such loss-of-function alleles frequently behave recessively and underlie many inherited diseases, including Duchenne muscular dystrophy nonsense variants requiring read-through therapeu
Ref:
Lehninger Principles of Biochemistry, 8th ed., Chapter 27: Nonsense Mutation Premature Termination