The Lethal White Syndrome or the Overo Lethal White Syndrome is the worst genetic disease your Paint foal can be born with. As the name suggests, it mainly occurs in foals with a dominant white color pattern. Unfortunately, the victim of this lethal disease has two mutated genes that disrupt its intestines’ development; this underdevelopment of the colon renders it impossible to excrete fecal matter. Being an incurable disease, it is best to euthanize a foal with LWS to save it from a more painful death.