Question

You discover that the underlying cause of a disease is decreased expression of the protein X due to a lower amount of the mRNA encoding protein X in cells. You find the corresponding mutation in the genome related to this disease. What kind of defect caused by this mutation can create the defective expression of the protein X? Describe two possible mechanisms (there are many possibilities). The best answers will include the nature of the mutation and how it impacts each step of gene expression for each of the two mechanisms you select to describe.

Answer 1

The two possibilities are:

1. Frameshift mutation: insertion or deletion in the DNA sequence will lead to the shift in the way the sequence is read. If there is an insertion or deletion in such a way that a stop codon is read in between, there will be a lower amount of RNA formation and hence protein production.

2. DNA damage: any kind of damage to the DNA of the respective gene in a single strand or double-strand break is highly prone to errors in correction of the damage. This will affect the transcription process leading to lower amounts of RNA and hence lower protein production.