Question

A friend of yours claims to have identified a gene that causes a human disease! Your friend says that they have sequenced the DNA of someone with the disorder and compared that to a healthy individual. They found a nucleotide difference in a gene called Hsr12 that encodes a protein whose function is cell-to-cell communication. What is wrong with your friend's claim?

Answer 1

Answer: Point mutation is easily reversible, thus non-lethal

Explanation:

Point mutation is caused by exchange of a single nucleotide for another. These change is called

1) Transition (when a purine base substitute another purine base, or pyrimidine bases substitute each other)

2) Transversion (when a purine base substitute a pyrimidine base).

However, note that a point mutation can be easily reversed by another point mutation; so, the claim that a nucleotide difference in the Hsr12 gene caused the human disease is inaccurate