A new XPC gene splicing mutation has lead to the highest worldwide prevalence of xeroderma pigmentosum in black Mahori patients

► Description of the highest prevalence of XP patients in the world. ► Differences between types and sites of cancer in black versus white XP patients. ► A new XPC gene splicing mutation causes 3 mRNA isoforms and absence of XPC protein. ► This mutation represents a founder effect estimated to be as old as 770 years. ► Detection of this new mutation allows early diagnosis of black XP patients.