Thanks for posting this and perhaps it is an opportunity to get the 
discussion away from conspiracies and AIDS.

I haven't had time to take a close look at the Nature Genetics paper, 
and it would certainly  be wonderful if the report was true and 
significant, but after more than 30 years of behavioral genetics 
raising false hopes I would point out a few cautions before one accepts 
this work quite yet.

First, in order to enhance their chance of finding a genetic cause, the 
  investigators had to limit their cases to those in which families 
showed multiple incidences of autism. This is a perfectly reasonable 
approach, BUT we need to know what percentage of the cases of autism 
fit into this model. If only 5% of the families that have an autistic 
child have multiple autistic children you may be studying something 
that, while interesting, may only apply to a minority of the cases.

Second - there is always the danger of using a single term to describe 
a multiplicity of illnesses. Is autism really only one condition? I 
have no idea, but one needs to be cautious in deciding if any 
information is generally applicable.

Third - the news release mentions "interaction between several genes" 
and so far it appears that many behavioral problems stem not from the 
strong effect of a single gene (example - sickle cell anemia) but 
rather from the weak effects of multiple alleles plus pre and/or 
postnatal developmental conditions.

I could continue with several other caveats - and while I hope the 
neurexin 1 really is a key player and that it leads to earlier 
diagnoses and  perhaps even treatments, if history is any guide these 
types of announcements are too often driven by the expiration of one 
grant and the need to convince an agency to fund a renewal. I would 
love to be wrong.

Ross Feldberg