Achange in the natural sequence of bases in dna structure is called a

A change in the natural sequence of bases in DNA structure is called a mutation.

1. Point mutation - This mutation result in the change of single nucleotide in the given DNA sequence. For e.g in a sequence AGGAATC if G changes to C the new sequence would be ACGAATC and this is called a point mutation.

2. Frameshift mutation-This mutation refers to the alteration of the open reading frame of a sequence due to insertion or deletion of several nucleotides in a sequence for e.g if you have a sequence AAATTGG and there is a deletion of AATT  you get AGG. This is an example of a frameshift mutation.

not sure if this is what you'r looking for nnew= nold