It should be taken into consideration the presence of frameshift mutations. Frameshift mutation, due to addition or deletion of a base, results in the change of reading frame and consequently in changed protein. But it is known that 3 nucleotides on mRNA code for the specific amino acid. If the number of inserted or deleted nucleotides is 3, it will result in the absence of only 1 amino acid which is not expected to drastically change protein sequence.
Knowing all this, it can be concluded the following:
-/-/+/-/- OK - Due to 4 deletions and 1 insertion, effectively only 3 nucleotides are missing.
+/-/+ Not OK - Due to 1 deletion and 2 insertions, effectively only 1 nucleotide is added leading to the frameshift mutation.
+/-/+/- OK - Due to 2 deletions and 2 insertions, a number of nucleotides remain the same.
+/+/-/+ Not OK - Due to 1 deletion and 3 insertions, effectively only 2 nucleotides are added and the frameshift mutation occurs.
-/+ OK - Due 1 deletion and 1 insertion, a number of nucleotides remain the same.
- Not OK - Due to 1 deletion, the frameshift mutation occurs.
-/-/-/-/-/- OK - Due to 6 deletions, it will be deleted 2 amino acids and the protein will be nearly normal.
+/+/+ OK - Due to 3 insertions, 1 amino acid will be added in excess.
-/- Not OK - Due to 2 deletions, the frameshift mutation occurs.
