What would least likely result from a chromosomal change?

A chromosomal change is least likely to result in a minor or insignificant change in an organism's phenotype if the alteration occurs in non-coding regions of DNA or if it involves redundancy in the genetic code. Such changes might not affect gene expression or protein function. Additionally, some chromosomal changes, like certain types of duplications or deletions, can lead to neutral variations that do not significantly impact the organism's overall fitness or development.