To our knowledge, the only reported epidermolysis bullosa (EB) type that was unlinked to the HLA system is the benign dominant EB simplex, Ogna's type.1,2 In this study, we report absence of close linkage, and, therefore, exclusion of true association for seven other genetic types of EB. A tabulation of HLA types in patients with recessive EB is fully consistent with the absence of association but illustrates the inefficiency of pure association tests between Mendelian traits as compared with linkage analysis via family studies.
Patients and Methods
The families with EB comprise patients who have been previously described3-8 and additional patients of Norwegian, Swedish, German and Irish-English origin. Clinical genetic classification includes old and recently established entities (Table 1).4 The HLA types in Table 2 were investigated from 1972 to 1976.The data in Table 1 exclude close linkage in terms of negative lod scores (lods), ie,