Synaptic Impairment, more commonly referred to as SI, is the disorientation illness experienced by the users of the Genetic Replicator network.

Usually manifesting as mental sluggishness, dizziness and nausea, scientific theories suggest that the symptoms - which last anywhere from a few seconds up to a few minutes - are created from the rapid disintegration and reassembly of a person's cellular structure. Up to now, there has been no progress on finding ways to counteract or eliminate the symptoms.