euphenics
noun
eu·phen·ics yü-ˈfe-niks 
plural in form but singular in construction
: the therapeutic techniques and procedures for amelioration of the deleterious phenotypic effects of a genetic defect especially without altering the genetic makeup of the germplasm of the individual
euphenic
yü-ˈfe-nik
adjective 
Word History
Etymology
eu- + phen- (in phenotype entry 1) + -ics, by analogy with genotype entry 1 : eugenics
Note: The term was coined by the American molecular biologist Joshua Lederberg (1925-2008) in "Molecular Biology, Eugenics and Euphenics," Nature, vol. 198, issue 4879 (May 4, 1963), pp. 428-29.
First Known Use
1963, in the meaning defined above
Medical Definition
euphenics
noun, plural in form but singular in construction
eu·phen·ics yu̇-ˈfen-iks
: the amelioration of the deleterious phenotypic effects of a genetic disorder (as phenylketonuria) that involves treatment (as a change in diet) that alters the environment but not the genetic makeup of an individual