Dr. Manny Says Autism Breakthrough Is Real...For NowThe comments were soon filled with the standard anti-vaccine rhetoric, government conspiracy claims, and general dislike for the medical industry. But what really surprised me was a supposed "Dr." posting the following:
By Dr. Manny Alvarez
Published June 09, 2011 | FoxNews.com
…[W]hen you look at a family that delivers twins, and one is autistic and the other is not, as a scientist, I have to believe there is a genetic component to the problem.
The studies, published in the journal Neuron, appear to have proven as much. The researchers examined the genomes of more than 1,000 families in which one child was autistic and the siblings and parents were not. Their findings confirmed a growing body of evidence that autism can be caused by a random genetic mutation that could occur at any one of hundreds of different sites in the human genome.
On behalf of my son, who was born with autism, and my family, I just want to congratulate the men and women who spent years working on this research.
Sorry to rain on your parade, Dr Manny, but twins are GENETICALLY IDENTICAL. If genetics were the cause, BOTH would be autistic.I wrote a detailed response to this and waited several hours, while the response count went from 20 to 50 to 70. I then write another comment, but not as a reply. Again, it was detailed but in "plain English" (at least as plain as science can be and still be accurate).
Fox News decided not to post either comment. Yet they were quick to approve conspiracy nonsense I am accustomed to reading on the Huffington Post website when it comes to autism. It is as if the one thing left and right wingnuts can agree upon: autism is a conspiracy. What follows is roughly what I posted to Fox, and I've attempted to post similar comments to HuffPost and other sites (CBS) doing a poor job explaining the science.
Genetics and Autism: An Explanation
Much of the recent genetic research concerning autism highlights the likelihood that de novo genetic mutations are at least partially responsible for some variations we call "autism." The challenge in explaining these studies involves misunderstandings of "genetic" and "early stage mutation."
"Genetic" is not a synonym for "hereditary" but hereditary traits are genetic. Genetic merely refers to any situation involving genes -- and there are genetic injuries that occur long after conception. Apparently, even a "doctor" can confuse the two concepts. Genes might pass along traits from our parents, but from the moment we are embryos changes can take place altering those genetic predispositions.
The "de novo" mutations discussed in these three studies refer to errors often found occurring after stage 16 of embryonic development. In the standard "stages" scale, stages 16 and 17 are approximately between 38 and 44 days after conception. During stage 16 and 17 the neurological development begins. Any errors in the replication process during these few days can have critical implications. The parents' genetics might or might not predispose an embryo to genetic errors -- we do not know for certain.
The errors discussed in the papers reviewed by the FoxNews medical correspondent are what we call "copy number variation" (CNV) mutations. Anywhere from 5% to 15% of our genetic makeup contains "errors" compared to the genetic information passed along from our parents. Why this happens is unclear, but that variation is probably beneficial evolutionarily. All species seem to have some CNV mutations, likely allowing traits to emerge with beneficial traits surviving.
CNVs might be swapped, missing, or duplicated genetic information. In any set of 100 nucleotide bases, five or more will likely be "errors" in the replication process. Therefore, even identical twins aren't identical. But, we also know that the CNVs generally affect weakly-transmitted characteristics. For example, hair color or eye color are "strong" genetic characteristics and unlikely to be altered by CNVs.
While we don't know why genes get mixed up, we can demonstrate definitively that no two children, not even identical twins, have identical DNA. Identical twins simply have an overwhelming number of similar genes -- but contrary to popular belief, they cannot be perfect copies of each other. No child is born without at least some CNVs.
We also do not know why some CNVs are serious and some are not. There are many things we do not understand, yet, about genetic contributors to autism and other traits. However, we do know genetics play an important role.
Genetics are complex, but the key is knowing that the complexity seems to naturally result in variations. Some variations, like perfect pitch or a photographic memory, seem desirable. Other variations seem to be less desirable.
We seem unwilling to accept that some things really might be random. We want to believe every event correlates to a cause. Geneticists, however, cannot explain the random mutations that every one of us has.