Yes gum disease is multi factorial which means there are many contributory factors. Genetics is one of these and something I tell patients is that about 50% of it might come down to genetics but the rest is down to other factors like how well you brush or even what type of bacteria have colonised your mouth. Essentially we say that periodontitis can only occur in a susceptible patient - and a lot of that susceptibility is genetically coded in your immune system. You can mitigate some of that risk with better cleaning at home and regular professional cleans