Final answer:
A frameshift mutation, such as the deletion or insertion of a single nucleotide in the hemoglobin gene, is likely to have a significant and detrimental effect on the gene's function, potentially leading to diseases like sickle cell anemia.
Step-by-step explanation:
Mutations in the hemoglobin gene can occur in various forms, each with different potential impacts on the gene's function. A point mutation, which involves the substitution of a single base nucleotide for another, can sometimes result in diseases such as sickle cell anemia, where a single amino acid substitution in the beta chain of hemoglobin is responsible for the disease. However, frameshift mutations, such as the insertion or deletion of one nucleotide (not multiples of three), can be much more detrimental as they alter the reading frame of the gene. This misreading of the genetic code from the point of mutation onwards leads to a completely different sequence of amino acids being synthesized, usually resulting in a nonfunctional protein. Conversely, if three nucleotides are inserted or deleted, the reading frame is preserved, and the protein may still function, albeit with some differences from the normal protein. Thus, for a mutation in the hemoglobin gene to be categorized as a likely candidate for consequential alteration, a frameshift mutation, particularly via deletion or insertion of a single nucleotide, would be a probable cause.