Hypomelanosis of Ito associated with benign tumors and chromosomal abnormalities: a neurocutaneous syndrome.

A 14-year-old Japanese boy with hypomelanosis of Ito (HI) who has been followed up from the neonatal period is described. In addition to neurocutaneous symptoms consisting of intractable epilepsy, severe mental retardation, sensory neuropathy and cutaneous hypopigmentation, the following abnormalities were detected; a ventricular septal defect, a mature cystic teratoma in the posterior mediastinum, a diploic epidermoid cyst of the parietal bone and chromosomal abnormalities, i.e. mos, 45, XY, t(14q 21q)/46, XY, t(14q 21q)+mar. This disorder showed not only multisystem involvement but also tumor formation, which had not been reported previously. Because of this, it is better to use the term "Ito syndrome" instead of "HI" or "incontinentia pigmenti achromians (IPA)," which emphasize only the cutaneous symptoms.