Is the severity of a stutter (also) mostly genetic?

Is the severity of a stutter (also) mostly genetic? Having a stutter is (mostly) genetic. It runs in my family (on both sides, yep…). But is the severity (mild, moderate, severe) also genetic? Unfortunately, in my family (definitely on my mom’s side, my dad’s side I’m not sure), it tends to be on the severe side. My uncle for example, had a severe stutter up until his twenties I got told, and he had his stutter since he could talk basically, so he was very, very little. Now he had a mild one, it started really getting better in his twenties, like I mentioned earlier. I’d say mine is moderate, although thankfully it’s getting better every year. I hope I will be fluent by my twenties or at least very mild. Sometimes my stutter can be quite severe though, unfortunately. Is the severity (also) genetic?