C8 deficiency in a family with xeroderma pigmentosum. Lack of linkage to the HLA region

The present study describes a large pedigree (23 members) of a Tunisian family with C8 deficiency and with a high incidence of xeroderma pigmentosum. It is shown in this study that, although the C8 deficiency is transmitted as an autosomal trait (three homozygous and five heterozygous individuals), heterozygote carriers having half-normal levels of C8 functionally and immunochemically, there is no close linkage between the C8-defective chromosome and the HLA antigen. These observations are in contrast to studies of another family described by Petersen et al. (1) and Merritt et al. (2) where the C8-defective gene was closely linked to MHC. © 1977.