Genetic Alteration of Embryos

Abstract

Sometime in the next two years, clinical trials with human gene therapy will begin.1 The trials will be aimed at two rare, very serious single-gene defects. One is Lesch-Nyhan syndrome, a serious and nontreatable disesase characterized by mental retardation, cerebral palsy, self-mutilation, and an accumulation of uric acid in the body. The other is adenosine deaminase deficiency, a disease of the immune system that leads to early death. Like most single-gene defects, they cause their ill effects because the gene essential to turning on the production of a crucial enzyme is missing.