Question

Insertion/deletion (indel) mutations typically cause frameshift mutations.

a. What is meant by a frameshift mutation?
b. Describe two situations in which an indel mutation would not be expected to cause a frameshift.
c. How could an indel mutation arise spontaneously?
d. Name a disease resulting from insertions (hint: think about diseases that result form the process you identified in part c.

Answer 1

Answer a.
Frameshit mutations are insertion/deletion mutations wherein the addition or removal of a nucleotide causes the codon framework to change. Now the reading of 3 occurs in a different frame.

Answer b.
Indels in the non-coding regions of the genome.
Indels in the regulatory regions of the genome.

Answer c.
Errors in (or during) DNA replication can cause the spontaneous insertion of deletion of one nucleotide.

Answer d.
Tay-Sachs disease (A 4-base insertion in the hexA gene)