Critically ill patients require significant medical care and use limited healthcare resources. Furthermore, the mortality rate from most forms of critical illness is much higher than for noncritically ill hospitalized patients. Although genetic diseases increase mortality, most are easily identified at birth and have only limited treatments and prognoses. Recently, more subtle single nucleotide polymorphisms at key loci have been demonstrated to result in a profoundly different prevalences of acute illness and subsequent survival rates for subjects with apparently similar insults and otherwise similar phenotypes. With the maturation of the human genome project, this new discovery will allow for the characterization of individual subject's responsiveness and potential for recovery from a number of insults. This realization makes our definition of genetic diseases blurred and begs the questions, "Will these new insights allow for more effective healthcare resource utilization, as defined from patient, healthcare system, and societal perspectives?" and, perhaps more worrisome, "Should intensive care resources be limited to those with the greatest chance of benefit?" Similarly, as with other genetic predispositions such as cystic fibrosis and congenital hypercholesterolemia, to what extent should these data be available outside the patient-doctor relationship?