I saw this and was shocked and horrified.
But then I thought about it a little longer... It's not as if the girl is able to comprehend the world around her in the same manner as Helen Keller (who was blind, deaf and mute) for example, her motor responses are severely limited and she has the equivalent mental development of a three year old.
Then there is the issue of long term care, can her parents pick and carry her as they age and she grows heavier? Is she equipped to deal with the emotional traumas of puberty with such limited mental development?
Sure it's drastic, but it seems to be without precident thus far. I can't say I'm in favour but I understand the reasoning of her parents.