Incontinentia Pigmenti (IP, Bloch-Sulzberger syndrome, OMIM 308300) is a rare X-linked dominant genodermatosis, usually lethal in males in the prenatal period. Wide spectrum of clinical expression consists of skin hyperpigmented lines and swirling patterns, dysplastic teeth and nails, and in 30% central nervous system abnormalities including seizures, microcephaly and intellectual disability (10% of cases). In 80% of IP cases, the disease is caused by a large-scale deletion of exons 4 to 10 of the NEMO gene. Three cases of variable expression of Incontinentia Pigmenti are presented. In a one-year-old girl, her mother and grandmother molecular analysis revealed the same typical deletion of the NEMO gene. In the proband, characteristic skin lesions were detected located over the trunk and lower limbs. Characteristic evolution of the changes was observed. In the mother, expression of the disease was much milder, whereas in the grandmother lesions were restricted to the fingernails. Clinical characteristics and pedigree data are described.