Nonsense-Mutation

A nonsense mutation (also known as a nonsense mutation) is a type of mutation in a DNA sequence that results in a premature stop codon in the mRNA. This causes premature termination of protein translation and the formation of a truncated, often nonfunctional protein product.

Nonsense mutations can occur due to the replacement of a single nucleotide in the coding sequence of a gene with any of the three stop codons - UAA, UAG or UGA. This leads to the cessation of full-length protein synthesis.

Nonsense mutations are often associated with inherited genetic diseases. For example, cystic fibrosis is caused by a nonsense mutation in the gene encoding the CFTR protein. A truncated, defective CFTR protein cannot perform its functions in cells.

Another example is Duchenne muscular dystrophy, which is associated with a nonsense mutation in the dystrophin gene. The absence of functional dystrophin leads to progressive muscle weakness.

Thus, nonsense mutations represent an important class of mutations that can have serious consequences for human health. Their study is important for understanding the molecular mechanisms of hereditary diseases and searching for possible methods of therapy.