The Mallen Litter by Catherine Cookson

I'd like to bet in a few years' time his hair will be black as a sloe and very likely show the streak...He's a Mallen, if ever I saw one.'

Each generation of the Mallen family has been cursed with a dramatic white streak in their jet-black hair. Barbara does not have the visible streak to identify her as a Mallen, but she has spent her life trying to forget her parentage - and the horrific circumstances behind her birth. When her triplets - the Mallen litter - were born, she hoped that it would herald a new beginning. But it seems that one of her sons bears the Mallen streak - and that the Mallen curse will never die out...