Q. "What is 'GH therapy', and why do children with Prader-Willi Syndrome often do this?"
My answer: "GH therapy" stands for growth hormone therapy. Children who have Prader-Willi Syndrome are, very often, given daily injections of human growth hormone. In June 2000 growth hormone was the first (and to date the only) drug approved by the U.S. Food & Drug Administration (FDA) for the treatment of Prader-Willi syndrome. GH therapy, if not covered by health insurance (or Medicaid, or a combination) would cost around $12,000 a year. Families living outside the United States often have a much more difficult time starting their children on GH th. before the age of two, and sometimes it is difficult to obtain it at all. It has been shown, by clinical studies done within the last 5 years, that GH therapy can (in most cases) be safely begun in infants, and also that it continues to provide benefits in individuals-with-PWS all the way up through adulthood. However, GH therapy is not a "cure" for PWS. It definitely does help make some aspects of the syndrome more manageable. But it is not a mandatory treatment, and there are parents who choose not to pursue it with their child.
So, what does GH th. do for individuals with PWS? Well, that word "growth" provides some idea of the benefits of the daily injections. But there is a whole list of benefits, "including but not limited to improvements in lean body mass, decreased body fat, increased bone mineral density, normalization of adult height, improved strength, agility, motor development, improved nitrogen balance, and improved energy expenditure" (quoted from the Clinical Advisory Board Consensus Statement from PWSA(USA.) ). For S, I firmly believe that she would not be doing as well as she is, at the moment, had we not started GH therapy. We began this with her when she was just 10 months old, but clearly, reading the above list of benefits of the therapy and having met adults who have recently begun GH shots, it is beneficial for individuals-with-PWS regardless of when they begin it.
S does not mind the injections. Even with the heightened pain tolerance which is part of the syndrome, she does still feel the needle, but I think she is used to it, and B and I just get through it and make as little fuss about it as possible. If we were to really zero in on whatever pain she might feel from the injections, the process would quickly become a huge production - and I have no desire to have to pin S down to do the shots. I'm sure she feels it. She occasionally has bruises in her injection sites (left and right thighs, left and right buttocks). In time we may be able to add left/right sides of the abdomen as well). At some point she will probably be really excited to be able to give herself the shots - she is really, really interested in anything medical in nature (she'd probably request her own box of those plastic gloves).
So, that is my "explanation" of growth hormone therapy!