I've typed up a couple of paragraphs:
A few hundred boys and men alive in the United States today have been diagnosed as having Lesch-Nyhan syndrome. . . . One boy, known as J.J., ended up living in Nyhan's research unit for a year, when he was eleven. He was a gregarious child, whose hands seemed to hate him. Over time, his fingers had got inside his mouth and nose and had broken out and removed the bones of his upper palate and parts of his sinuses, leaving a cavern in his face. He had also bitten off several fingers. J.J. died in his late teens . . . .
A Lesch-Nyhan person may be fine for days, until suddenly his hands jump into his mouth with the suddenness of a cobra strike, and he cries for help. People with Lesch-Nyhan feel pain as acutely as anyone else does, and they are horrified by the idea of their fingers or lips being severed. They feel as if their hands and mouth don't belong to them and are under the control of something else. Some Lesch-Nyhan people have bitten off their tongues, and some have a record of self-enucleation--they have pulled out an eye or stabbed it with a sharp object. . . .