CELTIC ANCESTRY, HLA PHENOTYPE AND INCREASED RISK OF SKIN-CANCER

Individuals of Celtic ancestry are claimed to be at greater risk of sk in cancer than non-Celts, and various positive and negative associatio ns between certain human leucocyte antigen (HLA) phenotypes and the de velopment of skin cancer have been described, The aims of this study w ere to determine whether any HLA phenotypes are associated either with Celtic or non-Celtic ancestry, or skin type, One thousand and ten mem bers of the Welsh Bone Marrow Donor Registry (WBMDR). whose HLA phenot ypes are known, were asked to complete a questionnaire which enquired as to their family origins and their 'Index of Celtic Ancestry' scored out of 12, Three groups were identified; non-Celts (score <3), Celts (score >9), and a subset of the Celts-'high scoring' Celts (score > 10 ), Details of hair and eye colour and skin type were also requested, S kin type and HLA-A. -B, -DR and DQ frequencies were compared between t he three groups (Celts, non-Celts and 'high scoring' Celts), and a ran dom indigenous population of 9196 members of the WBMDR, Seven hundred and thirty-six replies were received (279 male, 457 female, mean age 3 1 years), One hundred and forty-four Celts, 51 'high scoring' Celts an d 170 non-Celts were identified. Forty-six (32%) Celts had skill type I or II compared with 36 (21%) non-Celts (P = 0.039), and 37 (73%) 'hi gh scoring' Celts had skin type I or II (P < 0.0001). However, there w ere no significant differences between the groups with regard to hair colour, eye colour or number of episodes of painful sunburn. The frequ ency of HLA-DR4 was 32% in the non-Celtic group, 44% in the Celtic gro up (not significant), and 53% in the 'high scoring' Celts (P=0.008). H owever, the difference was not significant after correction. There wer e no significant associations between skin type and HLA phenotype. HLA -DR4 is known to be associated with an increased risk of both basal ce ll carcinoma and malignant melanoma and its increased frequency in Cel ts may be an independent risk factor for skin cancer in addition to sk in type.