Is diet an important factor in behavior? There have been claims that up to 25% of the autistic population may overproduce purines. The diagnosis of "purine autism", however, is a laboratory diagnosis and one must quantitate the excretion of uric acid in the urine over a 24 hour period. Furthermore, this must be done early on, as the biochemical finding disappears during adolescence. Identification during infancy would be ideal, but it is exceedingly difficult to obtain a 24 hour urine collection in infants. One clue, however, might be the observation of pink urine in a young infant, as the pink color is due to the presence of uric acid crystals. I have seen many infants who have had an episode or a few episodes of pink urine, as this is a finding that will almost always cause a parent to bring their infant to the doctor. However, I have never known one of these infants to go on to have a diagnosis of autism.
If you want to find out more about purine autism, go to the following website: http://www.purineresearchsociety.org/