When a closed circular chromosome is replicated, it produces two topologically connected daughter chromosomes, comparable to chain links.
The process of detaching this physical relationship is known as decatenation.
The decatenation checkpoint prevents the cell from entering mitosis until the chromosomes are separated.
During mitosis, chromosomal breakage and nondisjunction can occur, resulting in aneuploidy and chromosome rearrangements in the daughter cells if the decatenation checkpoint is defective or bypassed.