In genetics, a nonsense mutation is a point mutation in a sequence of DNA that results in a premature stop codon, or a nonsense codon in the transcribed mRNA, and in leading to a truncated, incomplete, and nonfunctional protein product.[1] Nonsense mutation is not always harmful,[2] the functional effect of a nonsense mutation depends on many aspects, such as the location of the stop codon within the coding DNA.[2] For example, the effect of a nonsense mutation depends on the proximity of the nonsense mutation to the original stop codon, and the degree to which functional subdomains of the protein are affected.[3] As nonsense mutations leads to premature termination of polypeptide chains; they are also called chain termination mutations.[4]
Missense mutations differ from nonsense mutations since they are point mutations that exhibit a single nucleotide change to cause substitution of a different amino acid. A nonsense mutation also differs from a nonstop mutation, which is a point mutation that removes a stop codon. About 10% of patients facing genetic diseases have involvement with nonsense mutations.[5] Some of the diseases that these mutations can cause are Duchenne muscular dystrophy (DMD), cystic fibrosis[6] (CF), spinal muscular atrophy (SMA), cancers, metabolic diseases, and neurologic disorders.[5][7] The rate of nonsense mutations is variable from gene-to-gene and tissue-to-tissue but gene silencing occurs in every patient with a nonsense mutation.[5]
https://en.wikipedia.org/wiki/Nonsense_mutation
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