A baby born with a rare and dangerous genetic disease is thriving after receiving an experimental tailor-made gene editing treatment. KJ Muldoon was diagnosed shortly after birth with severe CPS1 deficiency, estimated to affect one in a million babies. Affected infants lack an enzyme needed to remove ammonia from the body, meaning it can build up and become toxic. Researchers says KJ is among the first to be successfully treated with such a bespoke therapy, and hope the technology can help many