genetic interaction (sensu unexpected) surpassing genetic interaction orchard 2013-06-05T21:04:18Z PSI-MI MI:1286 An effect in which the observed phenotype of a double perturbation is opposite (relative to the wild type phenotype) to that which is expected upon the double perturbation. With respect to any single quantifiable phenotype, this may be expressed as an inequality as: ab < wt < E OR E < wt < ab where 'ab' is the observed phenotype value of the double perturbation, 'E' is the expected phenotype value of the double perturbation, and 'wt' is the wild type phenotype value.