They went further. To make her more comfortable and to prevent her from being sexually molested, doctors surgically removed her breast buds and her uterus. While they were at it, they removed her appendix. Mr and Mrs X call this the "Ashley treatment". Mr and Mrs X are loving parents. They call their daughter a "pillow angel" because she stays wherever they leave her. Instead of feeling sorry for themselves, they insist that Ashley "brings a lot of love to our family and is a bonding factor in our relationship". In fact, her parents, who have two other children, want to care for her as long as possible. But they fear that the larger she grows, the more difficult it will become.

The intentions of Mr and Mrs X are benign. But have they made the right decision in stunting their daughter's growth, lopping off her breasts and neutering her, especially since none of these are of direct medical benefit? The case has created a blizzard of controversy. A number of bioethicists supported what the couple did. But others contended that reshaping Ashley's body for the convenience of her carers was wrong. "Keeping Ashley small is a pharmacological solution for a social failure - the fact that American society does not do what it should to help severely disabled children and their families," declared the bioethicist Arthur Caplan, of the University of Pennsylvania. Society is barely interested in such children.

Will the Ashley treatment work? There is no data to support the notion that mentally impaired young adults who are short and light are happier than taller and heavier ones. In any case, while the oestrogen may make her shorter, it may not reduce her weight. The Ashley treatment is a step into the unknown. These objections were barely canvassed by the media in their coverage of the "pillow angel". Why?

Probably because the solution, radical as it was, struck a chord with Americans. As the popularity of cosmetic surgery shows, they regard the body as a kind of appliance to be reshaped at will. Worried about ageing? Get a Botox treatment. Hate your weight? Try liposuction. Boys don't like you? Ask for breast augmentation. "You deserve to look as beautiful on the outside as you are on the inside" is a slogan of cosmetic surgery clinics. It's the first rung on the ladder of transhumanism, the wacky dream of transforming ordinary humans into X-Men. It is significant that Ashley's parents quoted comments on their daughter by the transhumanist writer George Dvorsky: "She will retain more dignity in a body that is healthier, more of a comfort to her, and more suited to her state of development." People feel disconcerted by the sight of an adult with the mind of an infant, but Ashley will still be a little girl at 60. The philosophy which underlies the Ashley treatment is that this little girl's body is just a tool of the spirit to be reshaped and redesigned at will. The real her is trapped inside a floppy, burdensome carcass. Her parents have remodelled her body to match her mind. But this is wrong. Inseparable from our minds, our bodies are also us, not an attachment to us. We are not less dignified if our minds are impaired; we are not less dignified if our bodies are impaired.

The Ashley treatment is being touted as a precedent. In its wake, despite protests from disability groups, desperate parents will start asking doctors to turn these unfortunate children into sexless dwarves at even younger ages. And the doctors and hospitals will agree - because it is cheaper and more convenient. It's bad enough when Michael Jackson and Elizabeth Taylor reshape their bodies to match their fantasies. But at least it is their choice.

Ashley has no choice. Her body has been remoulded to match her parents' dream of a child who is forever young and innocent - and conveniently small. Their intentions are clearly good but high-dose oestrogen treatment to stunt the growth of disabled children is an experiment which should happen only once. Michael Cook is the editor of the email bioethics newsletter BioEdge.