How do alkylating agents cause mutations?

Alkylating agents transfer groups of methyl or ethyl to bases or the backbone phosphate group. Consequently, the modified bases pair with the incorrect complement, which leads to loss of bases or direct disruption of base pairing. Either way, this results in defective DNA replication or repair.

Alkylating agents include mustard gas, vinyl chloride, nitroso amines, and ethyl nitrosourea. For instance, guanine that has been alkylated may be mispaired with thymine.

Alkylating agents used therapeutically frequently stop the spread of cancer by preventing DNA replication and drastically increasing the size of cancer cells.

Alkylating agents induce mutations by adding alkyl groups to DNA bases, disrupting normal base pairing and causing replication errors during cell division. This can lead to DNA mutations, affecting the cell's genetic information.