Chondrodysplasia punctata displays genetic heterogeneity. The differentiation between the rhizomelic type and the Conradi-Hünermann type is well known. In 1977, an X-linked dominant form was described as a third type. The syndrome of X-linked dominant chondrodysplasia punctata includes skeletal, ocular and cutaneous anomalies with asymmetric involvement of the body. The cutaneous signs and symptoms are characteristic: congenital ichthyosiform erythroderma with linear and patchy hyperkeratoses; ichthyosis in the older child; linear and blotchy atrophoderma mainly involving the hair follicles; circumscribed alopecia; coarse, lusterless and irregularly twisted hair; sparse eyebrows and lashes that grow in various directions; flattened nail plates and onychoschizia. A further case of X-linked dominant chondrodysplasia punctata is reported. The ratio of females to males is so far 40:0. Apparently, the underlying gene defect is lethal in male embryos. The linear and patchy pattern of skin lesions reflects functional X-chromosome mosaicism.