THE CLINICAL and genetic particularities of incontinentia pigmenti (IP) have attracted the attention of many authors since the X-linked dominant, male-lethal transmission of this trait was discovered.¹ Lately, the advances of molecular research have yielded fascinating new insights into this disorder.^2,3 As a provocative counterpart, Hadj-Rabia and colleagues⁴ present in this issue an almost exclusively clinical study elaborated in a rather traditional way. Although, in most of cases, the diagnosis was not confirmed by molecular analysis, the authors show that even today working in this manner can provide worthwhile information. Yet, all of the data regarding the frequency of associated anomalies should be taken with great caution because this is a retrospective study. The neonates with a diagnostic label of "incontinentia pigmenti" were not routinely seen by a dermatologist. Rather, the relevant information was obtained by reviewing the medical records of 43 girls and 4 boys referred to a children's hospital in Paris from 1986 through 1999. The authors come to the conclusion that the diagnosis was correct in only 40 cases.