The enzyme DNA ligase can be defined as the DNA joining enzyme. The DNA ligase joins smaller strands of the DNA making them into one continuous strand. The DNA ligase is responsible for the joining of the okazaki segments, and the repairs in the backbone of the DNA strands. If the levels of the DNA ligase will decrease in a person's body because of a mutation, it will be difficult to repair the DNA and join the okazaki segments and hence, the gene expression will be altered. The packaging of the DNA will be altered too, and the DNA will be present in a person's body in fragments. Hence, the DNA replication will lead to the formation of the multiple small fragments.