There has been a great deal of concern about “the removal of Rett syndrome” from the DSM-V. For those who aren’t familiar with the DSM, it is the Diagnostic and Statistical Manual of the American Psychiatric Association. Here is the issue: The DSM-IV had a category called Autism Spectrum Disorder. It included Autism and a few other things that were not exactly autism, but shared some features of autism. Included in the Autism Spectrum Disorder was Rett Syndrome. So it defined Rett syndrome as part of the spectrum but different from AUTISM itself. The new definition makes no mention of Rett syndrome and many people interpret that as saying that Rett syndrome has been taken out of the DSM.
MECP2 Duplication syndrome, of course, had not yet been discovered when DSM-IV was being designed so there is no mention of it, but presumably the same logic would apply.
Technically, it is true that Rett syndrome is no longer mentioned as a separate category and there is no specific mention of MECP2 Duplication Syndrome. This, however, may be a good thing. Up until now, the chief significance of the mention of Rett syndrome was that individuals with autism were excluded from being diagnosed with autism. The lack of mention of Rett syndrome as a separate category simply means that it is not automatically excluded.
The new definition of autism is purely clinical. It does not deal with causes. If any individual exhibits the symptoms of autism, he or she is diagnosed as autistic. So, individuals with Rett syndrome and MECP2 Duplication syndrome are not excluded, just like people with Fragile X syndrome or Down syndrome (both of which have higher than randomly expected rates of autism).
As more and more genetic causal factors for autism are identified it makes no sense to exclude those with specific genetic diagnoses and include those only with no specific medical diagnosis. We need to recognize that Autism can be secondary to Rett syndrome, MECP2 Duplication Syndrome, or a number of other conditions. We should not fight the proposed changes but rather we should be thinking aboout how best to work with it.