Hypomelanosis of Ito (HMI) is a rare skin condition characterized by hypopigmentation (unusual lack of skin color) caused by lack of melanin. Hypopigmentation may appear on any area of the body except the palms of the hands, the soles of the feet, and the scalp. Numerous other congenital defects may be present including neurological, skeletal, hair, and dental abnormalities. Causes of HMI elude re¬ searchers, but theories point to a chromosomal mosaicism (an occurrence in an individual of two or more cell populations of different chromosomal constitutions derived from a single zygote). Sporadic mutations also may occur. Intellectual and adaptive deficits are usually present.