We present a case of Incontinentia Pigmenti.

The mother exhibited characteristic skin lesions. Fetal imaging demonstrated a posterior cephalocele, seemingly isolated, in the female fetus. As a X-linked dominant disease, affected female fetuses have milder symptoms, because they have another copy of X chromosome bearing the wild-type (normal) allele. Affected females exhibit mainly skin and ectodermal anomalies, and sometimes central nervous system lesions, as in this case. Male fetuses, whose only allele is mutated, die in utero at the end of the first trimester showing signs of hydrops.