This is due to allegations of Dominic Cummings’ child being autistic. However there aren’t any material sources for this rumour so it’s Twitter journalism time.
I found the first instance of Cummings and autism being used together.
A fairly standard right wing repost account that starts with “Apparently”. Feel free to check time stamps against other tweets of 24/5/20. This was the first. And the trail went cold. So I reached out to this account asking where he found this information...