1. National Xeroderma Pigmentosum Service, St John’s Institute of Dermatology, Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
2. Paediatric Neurodisability Service, Rainbow House, Ayrshire Central Hospital, Irvine, NHS Ayrshire and Arran, Scotland, United Kingdom
3. Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton, United Kingdom
4. DNA Repair Section, Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland