I've been searching the net for some help with this. I have identical 14 yr old twin boys, both of whom have numerous moles over their bodies. I noticed about a yr or so ago that the one boy had a patch of gray hair. Since then I've noticed about 5-6 spots on his head that have about 20 or more gray hairs. Each cluster of gray seems to sprout from a light coloured non-raised mole. I've taken him to our doctor who admitted he'd never seen something like this and is in the process of researching it. He said it's likely nothing of concern but will probably refer him to a dermotoligist. Unfortunately - it could take several months to get in to see one. I should also add that he also has several body moles with white rings around them, which I pointed out to the doctor.
Family history of skin cancer, as far as I know is only 1 maternal uncle, of many relatives.
Obviously we're rather concerned. I've seen premature graying in teens - but it seems very odd to me given they're identical twins, no history of pre-mature gray in family, and sprouting from numerous moles.