Medical Genetics itrous acid is a deaminating agent Deaminating agents cause the loss of the amino group. We covered spontaneous deamination of cytosine above. Deaminating agents would increase the frequency of cytosine deamination greatly.Medical Genetics Nitrous acid is a deaminating agent. Deaminating agents cause the loss of the amino group. We covered spontaneous deamination of cytosine above. Deaminating agents would increase the frequency of cytosine deamination, greatly