Hi Jun Yi,
Thanks for your D2D. It is true that our looks are a result of our genetic makeup. Recently, there was a case where I had to treat 4 sibilings with similar eye bag conditions.
However, such an example of familial inheritance in features is not always the case. The cause of eye bags is a confluence of factors, bone structure, fat volume, skin laxity, and so forth. You can imagine that a patient with a shallow orbit (eye socket) and a large fat pad under the eye area will tend to exhibit an eye bag.
I hope this helps!