DD doesn't have a diagnosis yet, she's 6. She goes to Special school, but we don't know what her full condition entails.
From a very young baby:
Wouldn't sleep at night - literally. 10pm came and her alarm clock was on. She would cry/scream all night until about 7 weeks, then until 4am at about 9 weeks, then 1 am at about 10 weeks, then suddenly at 12 weeks would sleep from 7pm, but wake lots during the night.
I vividly remember putting her in her bouncy chair with an activity cradle over it at 3am once she was about 4 months old 
she just would not sleep but would quite happily sit in her chair bashing the cradle.
As a young child (6months plus) she was literally either on or off. I remember when she was 2yrs 9 months, the nurse at the hospital was amazed. She was screaming and crying in my arms that she didn't need a sleep. She was clearly tired. She quite literally went from crying and screaming to asleep, as if someone had unplugged her. She did that from 6 months on.
Once she could crawl, if we went anywhere, I had to ask the host to put any shampoo, toothpaste, showergel etc up somewhere high. She was like lightening and could get up the stairs, into the bathroom and squeeze stuff out before we could even get to her!
She had/has no sense of danger. Her condition has some physical limitations which have moderated her ability to endanger herself (she has a weak grip, wobbly feet, etc). But she still, despite this, climbs the trellis in the garden if my back is turned. We have to have stairgates everywhere. We have an electromagnetic lock on the door because she worked out that she could use a box to climb up and over; we live near a main road.
She's always talking (despite being speech delayed) always asking questions about what's next, etc. Never content to just 'be'. No concentration span.
The list goes on.