Researchers have discovered the genetic cause of a rare blood vessel disorder that can trigger life-threatening bleeds and strokes.

They believe targeted cancer drugs may be able to treat it, in patients like 13-year-old vlogger Nikki Christou.

Scientists at University College London Institute of Child Health and Great Ormond Street Hospital, who led the study, said it was an "enormous step" towards understanding and treating arteriovenous malformation (AVM).