Familial pervasive development disorder, Tourette disorder and hyperlexia.
Four children and one adult have been found to have Pervasive Developmental Disorder, Tourette disorder and hyperlexia in North Dakota, a state with a population of 204,161 children ages 0-18. Assuming that these are independent disorders the probability of these three disorders occurring by chance in one child is 3.39 x 10(-12). Two of these individuals are from the same family. This suggests evidence for genetic linkage among these three disorders.