Thanks to all on this thread for some very interesting and sensible cautionary posts, I agree it is nice to be able to discuss some real issues here. On the genetic findings, we have indeed been treated to claims about this and that gene before and things rarely turn out to be so simple. Always best to wait for the technical comments and followup studies.

Michael

On 2/19/07, Ross S. Feldberg <[log in to unmask]> wrote:
Laura

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



--
www.michaelbalter.com

******************************************
Michael Balter
Contributing Correspondent, Science
[log in to unmask]
******************************************