fetters:

This is a scan of a page in the January 2012 issue of National Geographic. In particular, it’s a page from an article about twins, and there’s a section in the article about two identical twins, John and Sam, who have both been diagnosed as autistic, but inhabit wildly different points on the autism spectrum. It’s really interesting to think about these boys who share the same genetic makeup, yet express very differently a disorder that is considered to be largely hereditary. John and Sam (and many other similar stories) have prompted some researchers to examine the role that epigenetics (variability in expression of the underlying genome) plays in autism. In the case of John and Sam, John needed to undergo heart surgery at a very young age (less than four months) and was on antibiotics for a long while after the procedure. Thus, in that crucial developmental period, John and Sam were in radically different chemical environments. How much of a role this could play in gene expression and, in turn, what role this could have in the development of autism are still very much unanswered questions, but they are promising lines of scientific inquiry.

Also, John and Sam are my brothers, and I think this is an absolutely adorable picture of them.