The answer to this is a nonsense mutation. This is a type of mutation wherein the supposed mutation in the sequence of DNA is suddenly halted. This means that the chain is suddenly stopped because of the chain-terminating codon that appears.
The protein that is formed because of this mutation is usually shorter and it is obviously incomplete which means that the protein that has been formed is also non-functional.
The amino acids are unable to complete their normal sequence because of this mutation. There are different gene mutations that may occur that will usually result in different health conditions.