Explanation:
n a point mutation, an error occurs in a single nucleotide. The entire base pair may be missing, or just the nitrogenous base on the master strand. For point deletions, one nucleotide has been deleted from the sequence. For example, if the original sequence is ATG-AGT-CGT-ATA-TAA, it will code for methionine, serine, arginine, isoleucine, and finally the STOP codon (telling the cell to stop protein production).
After a point deletion, the new sequence might be ATG-AGC-GTA-TAT-AA. In this case, a T has been deleted. The new amino acid sequence is methionine, serine, valine, tyrosine, and then the final AA doesn't code for anything.
While some amino acids may be the same, the deletion creates a frame shift, causing changes down the line.
Frame Shift
A chromosome deletion is also possible, where an entire section of a chromosome is deleted. This can involve any number of base pairs as long as it is more than one (that would be a point deletion). Sometimes an entire chromosome can be deleted as well. Whenever any DNA is deleted during replication, any number of genetic diseases can occur.