You are part of a group of researchers working on determining the genetic basis for early onset Osteoporosis. Using data from subjects in Iceland, you are able to identify where the mutation is located. The target gene in unaffected people produces the amino acid sequence Pro-Met-Glu-Arg-Asp. In individuals with the mutation, the protein produced has a sequence of Pro-Met- then stops. What type of mutation is this?

This question lacks options; the options are:

A) Deletion mutation

B) Missense mutation

C) Inversion mutation

D) Nonsense mutation

The answer is D) Nonsense mutation

Explanation:

A mutation in genetics refers to the change in the nucleotide sequence of a gene or DNA segment. The occurrence of mutation in a gene leads to different effects, which is the basis of the different types of mutation. The type of mutation described in this question is called a NONSENSE MUTATION, which is a type of base substitution mutation.

Nonsense mutation is the mutation in which one nucleotide base in the sequence gets replaced by a STOP CODON (UAA, UAG, UGA), leading to the truncation of the amino acid sequence and hence, the production of a non-functional protein.

This is the case in this mutated gene sequence whose normal sequence codes for: Pro-Met-Glu-Arg-Asp. The mutation causes the codon specifying Glutamine to be replaced by either of the STOP codons, thereby, stopping the translation process. The stop to the translation process causes the amino acid sequence to be truncated and a non-functional amino acid sequence is formed: Pro-Met-