I put this under milestones because it's partially involving milestones...but feel free to move it.

Hopefully quick background (I'm bad at being brief): T is 15 months. At 9 months he was barely sitting, so we started the long process of beginning EI. Finally got accepted and started at 12 months (still could only sit). In 3 months he's now progressed to crawling, pulling up, and a little bit of cruising. Great progress!

At his 15 month well visit, his doctor said his belly muscles were definitely weaker than they should be, and that it's probably just something he was born with. He told me this at his 12 month visit but I thought since he was doing much better with his milestones at 15 months that it would have gotten better (I don't know why I thought that necessarily).

He didn't touch much on this, because he is making excellent progress and as long as he's walking by 20 months he doesn't feel like we need to be much more concerned about his physical delay. I feel the same way but I was just Googling about low muscle tone and have a lot of questions. I wish I had probed more information out of him at the appointment but we were busy discussing other things and it slipped out of conversation and my mind.

If your LO has low muscle tone, is it just one region? T's arms and legs have always seemed strong enough. All of his physical delays have stemmed from his abdominal muscles.
Is it genetic? I read it could be genetic, and I've always been a weakling, even when working out a lot, although my mom says I hit my physical milestones as a baby on time.
If your LO is now older and fully walking/running/on track, do you still notice a lack of coordination or any sign that they have low muscle tone?

I know these are questions for his doctor, but it's 9pm at night and I'm just curious. Also sorry if these questions are dumb. I'm a little clueless, so any info would be appreciated!