For one thing, the term "Asperger's Syndrome" is itself considered out of date at this point, as it isn't distinguishable from high-functioning autism. And autism spectrum disorder may not be a binary yes-you-have-it or no-you-don't genetic condition so much as an epigenetic one.
[quote]Epigenetic processes [are] chemical reactions tied to neither nature nor nurture but representing what researchers have called a "third component." These reactions influence how our genetic code is expressed: how each gene is strengthened or weakened, even turned on or off, to build our bones, brains, and all the other parts of our bodies.
[quote]If you think of our DNA as an immense piano keyboard and our genes as keys—each key symbolizing a segment of DNA responsible for a particular note, or trait, and all the keys combining to make us who we are—then epigenetic processes determine when and how each key can be struck, changing the tune being played.
[quote]One way the study of epigenetics is revolutionizing our understanding of biology is by revealing a mechanism by which the environment directly impacts genes. Studies of animals, for example, have shown that when a rat experiences stress during pregnancy, it can cause epigenetic changes in a fetus that lead to behavioral problems as the rodent grows up. Other epigenetic changes appear to occur randomly—throwing a monkey wrench into the engine of nature versus nurture. Still other epigenetic processes are normal, such as those that guide embryonic cells as they become heart, brain, or liver cells, for example.
[quote]"During pregnancy, many changes must occur as cells commit to and become progressively specialized tissues, and we know that process involves a cascade of epigenetic programs," says Andrew Feinberg, director of the Center for Epigenetics at Johns Hopkins School of Medicine.
[quote]Feinberg's study focuses on a particular epigenetic process called DNA methylation, which is known to make the expression of genes weaker or stronger. To better understand how it relates to autism, Feinberg and his team are using scanners and computers to search samples of DNA from autistic twins for epigenetic "tags," places along the genome where methylation changes the pattern of gene expression.
[quote]The goal of the study, still in progress, is to determine whether individuals with severe autism have different methylation profiles than other people. Despite sharing the same keyboard, their bodies [may be] playing different tunes.
[quote]Scientists are only beginning to understand how epigenetic processes relate to complex disorders like autism. The good news is that some of these processes, unlike our DNA sequences, can be altered. Genes muted by methylation, for example, sometimes can be switched back on again relatively easily. And though it may not happen soon, the hope is that someday epigenetic mistakes will be as simple to repair as a piano that's out of tune.