The case of a newborn boy with ichthyosiform erythroderma, asymmetrical shortening of the femur and sectorial cataract is reported. The hyperkeratotic areas cleared within 2 months, resulting in follicular atrophoderma. The clinical findings and course of the disease, and also the histological and ultrastructural features, indicate an X-linked dominant chondrodysplasia punctata (Happle). Since a normal male karyotype (46, XY) is present, a half-chromatid mutation of the maternal gamete and a somatic mutation are considered as possible explanations for this mosaic phenotype.