Xeroderma Pigmentosum is a debilitating rare disease characterised by hyperkeratinisation, poikiloderma and wider skin tissue damage that is a consequence of irreparable DNA damage. Affected individuals are particularly susceptible to developing actinic keratoses and squamous and basal cell carcinomas due to a genetic defect which hampers the nucleotide excision repair (NER) process. Eye and neurological problems are likely to occur over time, but neurological defects only develop those with the greatest impairment of DNA repair.
Due to these genetic deficiencies in DNA repair proteins, XP patients are 10,000-fold greater risk of developing skin cancers including melanoma, necessitating them to shield from ambient and outdoor light from birth onwards. The extreme rate of these malignancies requires frequent surgical removal that often results in loss of extremities and facial anatomy, such as ears, and eyesight. The median age of survival for XP patients is approximately 30 years.