I just heard on the news today, that they think they have finally linked it to a specific gene...
I would be interested to know if it has always been in the genes, or if something has happened to alter the genes over the course of time...
When my niece was diagnosed in 1990, she had to be taken to a major medical center for a proper diagnosis... We were told that it was a fairly common occurrence. Back then and before, it seemed to be "lumped in" without several other forms of mental retardation. Many doctors didn't know exactly what to look for, nor did the specialists who worked daily with handicapped children in the medical field or the school systems.
The school district in 1990 was also at a loss as to how to set up a proper learning environment for her.
10 years later, she could get more of the proper help/care much closer to home... Now most of her specialist know of the condition or at least enough to make informed decisions for her various medical/mental issues/treatments.
So I guess I would have to say it has been around for a long time, it just didn't have it's own specific title.
We also believe her blood uncle has it to a lessor degree, he however refuses to go in for a diagnosis. He is 52 yrs old.
I think another problem is that there can be other mental/medical problems that also help cloud making a proper diagnosis. Some also have schizophrenia or other mental conditions, as well seizures and other disorders.
There is not just one test to determine if a person has autism, it is a series of test and observations.