Hypomelanosis of Ito associated with chromosomal translocation involving Xp11.

We report on a 3-year-old girl with hypomelanosis of Ito (HI). She has typical skin lesions and mild CNS involvement characterized by impaired walking and borderline mental retardation. Cytogenetic investigation showed a 18/X translocation with breakpoint on Xp11. This is the sixth case of HI in which this breakpoint has been reported, underlining that this event cannot be considered coincidental. Further studies are needed to understand the etiologic and pathogenetic meaning of this finding.