Difference Between Missense and Nonsense Mutation

Missense and Nonsense mutations are the two different types of point mutations also known as single nucleotide substitutions that introduce changes in the ultimate protein product. DNA in the body changes because of various internal and environmental factors. Due to this two types of changes that occur in DNA are DNA damage and DNA mutations. The below article covers the two such mutations that occur in DNA.

Difference between Missense and Nonsense Mutation

Below are the differences between missense and nonsense mutation:

Parameter	Missense Mutation	Nonsense Mutation
Definition	A missense mutation is defined as a type of mutation where the substitution of different amino acids takes place into the amino acid sequence that results in nucleotide change.	Nonsense mutation is defined as a type of mutation where a premature stop codon is introduced into the mRNA sequence that results in a nucleotide change.
The type of codon introduced	Missense mutation introduces a distinct codon.	Nonsense mutation introduces a stop codon at the site of mutation.
Results into	Missense mutation results in a distinct amino acid.	Nonsense mutation results in the termination of a premature chain.
Type of protein resulted	Missense mutation results into an incomplete protein.	Nonsense mutation results into a conserved protein.
Type of proteins produced	Missense mutation produces proteins that are non-functional.	Nonsense mutation produces proteins that are functional, non-functional or can have a distinct function from the original proteins.
Final product	Missense mutation results in a different amino acid sequence as a final product.	Nonsense mutation results in a unfinished or short protein as a final product.
Leads to disorders	Missense mutation leads to genetic disorder such as Duchenne Muscular Dystrophy(DMD), Dravet syndrome and Hurler syndrome.	Nonsense mutation leads to sickle-cell disease, Mediated Amyotrophic Lateral Sclerosis(ALS) and Epidermolysis bullosa.

What is meant by missense mutation?

Missense mutation is defined as a type of mutation where substitution of different amino acid takes place into the amino acid sequence that results into nucleotide change. Missense mutation is also known as non-synonymous substitution. Stop codon is not generated in missense mutation for terminating the sequence of amino acid synthesis. In missense mutation if new amino acid consists of similar features as in the original amino acid, the missense mutation is called as conservative mutation. If new amino acid has different properties as compared to the original one, then this type of missense mutation is known as non-conservative mutation. The mutated protiens can become non functional or else can have different functions compared to original protein.

What is meant by nonsense mutation?

Nonsense mutation is defined as a type of mutation where a premature stop codon is introduced into mRNA sequence that results into a nucleotide change. There are three stop codons in the DNA sequence namely TAG, TAA and TGA. These three codons are then transcribed into mRNA sequence that produces three different types of nonsense mutations known as UAG(amber mutations), UAA(ochre mutations) and UGA(umber mutations). By the insertion or deletion of a single nucleotide in the nucleotide sequence these three different mutations can also emerge. In mRNA the remaining codons that are beyond the stop codon will not be translated and it leads to premature chain termination.

FAQs on Missense and Nonsense Mutation

1. What is the Difference between Nonsense and Missense mutations?

The difference between nonsense mutation and missense mutation is missense mutation is a type of mutation where substitution of different amino acid takes place into the amino acid sequence that results into nucleotide change whereas nonsense mutation is a type of mutation where a premature stop codon is introduced into mRNA sequence that results into a nucleotide change.

2. What is the Difference between Nonsense and Missense Mutations and Issues that can arise from both?

The difference between issues that arises from nonsense and missense mutations is nonsense mutation introduces a stop codon that prevents proteins from being made completely and missense mutation changes the amino acids that are incorporated into the proteins.

3. What is an Example of a Nonsense Mutation?

Beta thalassemia is a example of nonsense mutation. Beta thalassemia is caused in beta-globin chain of hemoglobin protein. In RBCs hemoglobin is considered as the main oxygen-carrying protein. The patients who suffers from beta thalassemia do not have proper oxygen levels for reaching their vitals.

4. Why is it called a Nonsense Mutation?

Stop codons do not code for amino acids rather they signal the end of protein synthesis. Therefore it is known as nonsense mutation.

5. What is the most Common Cause of Nonsense Mutation?

The most common causes of nonsense mutation are substitution of a single base pair in a triplet codon that leads to one of the three stop codons namely UAA, UGA and UAG.