There is only one diagnosis of Autism. 

High-functioning/Low-functioning Autism are distinct disorders, in my opinion.

We know of the different facets of Autism, ASD, Asperger Syndrome, whilst little of the most debilitating form, Low-functioning Autism, a definition of convenience. In fact, I consider it a full-blown Psychosis.
I still remember my brother’s first diagnosis: Infant Syndrome Psychosis.The psychiatrist wrote Autism when he was institutionalized…

The fact that low-functioning autistics share these traits with their high-functioning counterparts doesn’t necessarily mean they’re autistic.

Would you compare a pluridecorate Asperger with a person who can’t read, write, dress up, like the ‘Autistic guests’ of my brother s community?! No way. 
Research is at a loss and understandably manipulated.

‘Functioning Autism’ has become a successful resume’ for smart people, I surely don’t see these people as sick.
These are the individuals always featured in the Autistic Community.

Nobody features my brother and his community in the media.

I do see ‘low-functioning Autism’ as illness, based on my brother who needs 24/7 assistance, formally diagnosed with Autism.

Are we talking of Illness or Personality?
Or something totally unrelated to Autism?

Has Autism become a diagnosis of convenience?

I look forward to your response.