For what it’s worth — i.e., I report, you decide. As for myself, I have neither done scientific research on this issue, nor have I studied it. But Wiley Long (M.S., Nutrition and Exercise Science), writing in the Paleo Diet Update (of which Mr. Long is editor), says:
There is growing evidence that the Paleo Diet can be beneficial to children with Down’s Syndrome, autism, and other genetic disorders affecting cognitive functioning. Prader-Willi syndrome (PWS) is a very rare and complex genetic disorder that typically causes low muscle tone, short stature, incomplete sexual development, cognitive disabilities, problem behaviors, and a chronic feeling of hunger that can lead to excessive eating and life-threatening obesity. You can read the account by a mother who put her 4 ½-year-old child with PWS on a Paleo-type diet about a year and a half ago at http://www.pwsnotes.org/User:PWSMom.