CorrespondenceHRAS mutation in phacomatosis pigmentokeratotica without extracutaneous diseaseAuthorsL. Jennings,Department of Dermatology, Beaumont Hospital, Dublin 9, IrelandSearch for more papers by this authorR. Cummins,Department of Pathology, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, IrelandSearch for more papers by this authorG. M. Murphy,Department of Dermatology, Beaumont Hospital, Dublin 9, IrelandSearch for more papers by this authorC.