Genetic Linkage Between the Collagen VII (COL7A1) Gene and the Autosomal Dominant Form of Dystrophic Epidermolysis Bullosa in Two Dutch Kindreds

Epidermolysis bullosa is a heterogeneous group of heritable blistering skin diseases affecting epidermis and the dermal-epidermal junction zone. Recently, genetic linkage to the type VII collagen gene (Z = 8.77; < = 0.00) localized on chromosome 3p21 was shown in three Finnish families with the autosomal dominant form of dystrophic epidermolysis bullosa. Two Dutch kindreds with intrafamilial characteristics of both the Cockayne-Touraine type and Bart's syndrome of autosomal dominant dystrophic epidermolysis bullosa have been studied. Two-point linkage analysis in these two families with the COLTA1 marker revealed a combined lod score of Z = 6.08 at θ = 0.00. These data strongly suggest that the type VII collagen gene is the candidate gene iii these Dutch pedigrees. At least two (Cockayne-Touraine and Bart) of the three subtypes of dominant dystrophic epidermolysis bullosa seem to represent different forms of expression of the same gene defect.