Xeroderma Pigmentosum
Background
Xeroderma pigmentosum (XP) is a group of rare inherited conditions that is characterised by defective repair of DNA damaged by ultraviolet light, particularly from the sun. There are at least eight different subtypes recognised, which are referred to as complementation groups A to G and XP variant. Each subtype has a different genetic abnormality and capacity to repair DNA. The subtypes show different degrees of severity.