As a kid, in the sixties, we were all prepared for first holy communion, over a number of weeks, and even though it was an oppertunity for a frock and a party,there was a lot of work before hand.
In my childhood down syndrome children were all in special schools and that was reflected throughout society,less was expected of them.
Now, down syndrome kids are main stream,and they are prepared at church in the same way,they are probably more supported,according to need, but they have to have an understanding of what they are doing, ive seen d.s kids receive communion.( My own kids had first holy communion 5-10 years ago)
The child may be a couple of years older than their peer group, but thats obviously liked to their learning ability
There seems to be an expectation here by the parents in A) not supporting the understanding of the mass with their boy, they admit he cant sit through a mass and b)crying descimination because they cant understand that it isnt just a photo opportunity and party.
This says more about the parents than their child.
The boy can still come up to recieve a blessing and be prepared in his own time . Some kids are ready at one age ,some ,a few years later. No ones going to point a finger.