A triangle of considerations—extraordinary suffering, highly penetrant genotypes, and justifiable interventions—has, thus far, constrained our attempts to intervene on humans. As we loosen the boundaries of this triangle (by changing the standards for “extraordinary suffering” or “justifiable interventions”), we need new biological, cultural, and social precepts to determine which genetic interventions may be permitted or constrained, and the circumstances in which these interventions become safe or permissible.
