Simple numerical descriptor for quantifying effect of toxic substances on DNA sequences.

Many chemicals are known to be toxic to living organisms, inducing mutations and deletions at the chromosomal and genetic level. One of the tasks in risk assessment of genotoxic chemicals is to devise a simple numerical descriptor which may be used to quantify the relationship between chemical dose and the effect on the genetic sequences. We have developed numerical descriptors to characterize different DNA sequences which are especially useful in sequence comparisons. These descriptors have been developed from a graphical representational technique that enables easy visualization of changes in base distributions arising from evolutionary or other effects. In this paper we propose a scheme to use these descriptors as a label to help quantify the potential risk hazard of chemicals inducing mutations and deletions in DNA sequences.