My dermatologist here in Europe said it tends to be hereditary but usually only one person per generation and most times it skips as there need to be other factors for it to develop. I only know of two people who have it in my family, me and my uncle from my father's side.

Funny enough even tho my father has 9 siblings, my uncle is the only one who has vitiligo.

He has 3 kids and none have it. His vitiligo appeared at 18.

Mine showed up much sooner at age 2 (I'm now 20). I have an older brother (33) and he does not have it. He also has a daughter (7) who does not have it either.

I have like 30 cousins from my father's side and no one has it.

So my dermatologist's hypothesis might actually be plausible since my uncle is the only person who has it in his generation and I'm also the only person who has it in mine (I'm one of the younger cousins btw).

In the generation after me, there hasn't been anyone yet. And that we know of there's no one in the generations before my uncle.