Loose Rivets,
Thre is always a genetic component to gout, but it can be aggravated by certain foods, the list of which I am sure you know well. In your case, getting it at a young age, when you were not obese and probably not over-indulging in forbidden foods or a bottle of Port a night points to a very strong genetic component in your case.
You can find out pretty easily, though, by cutting your allopurinol to 200mg daily, following a strict gout-avoiding diet and keeping an eye on your serum urate level. Then cut to 100mg if all OK and maybe even come off it completely. But if your urate starts to climb much above 0.42mmol/l you may be in for trouble and if you are doing everything you can on diet and are not obese then the majority of the problem is genetic.
All the usual caveats -- general advice only, do not change medication without seeing your own doctor, etc etc etc.
QDM