Hypomelanosis of Ito, also called incontinentia pigmenti achromians, causes streaked, whirled, or mottled patches of light-colored skin. These skin changes often develop within the first two years of life. Other symptoms may include varying degrees of learning disability, seizures, increased body hair, scoliosis, and strabismus. The exact cause is not known. Many people with hypomelanosis of Ito syndrome have cells that have the normal chromosomes and some cells with abnormal chromosomes. This is known as chromosomal mosaicism. This condition is not inherited in families. Girls tend to be affected more commonly than boys. Diagnosis is based on the symptoms, a clinical examination, and the results of a skin biopsy. Treatment is focused on managing the symptoms.

In many cases the cause of hypomelanosis of Ito can not be determined. Some cases have been associated with an underlying chromosomal abnormality. The skin patterning may reflect “mosaicism.” In mosaicism the person has some cells with normal chromsomes, and some with the chromosomal or gene abnormality. Click here to view an illustration of mosaicism. Mosaicism often leads to 2 cell lineages, which results in areas of hypopigmented (light areas of skint) and hyperpigmented skin (darker areas of skin). X-chromosome alterations are also found in hypomelanosis of Ito, and recent studies show that X-chromosome inactivation, activation, and mosaicism as the main causes of these differences in the skin. In less than 3% of the patients there is a family history of hypomelanosis of Ito–type skin lesions. Although hypomelanosis of Ito syndrome is most commonly a de novo occurrence (without any other cases in the family), familial cases appear to be transmitted as an autosomal dominanttrait. About 10% of the patients report a family history of seizures or epilepsy.

In less than 3% of the patients there is a family history of hypomelanosis of Ito–type skin lesions. Fmilial cases appear to be transmitted as an autosomal dominanttrait. About 10% of the patients report a family history of seizures or epilepsy. Cases of autosomal recessive, and X-linked inheritance has also been reported in the literature. Click on the links to read more about these different modes of inheritance by visiting the the MedlinePlus information pages on these topics. The risks for future offspring to inherit hypomelanosis of Ito would depend on the type of inheritance in the family (i.e., sporadic, autosomal dominant, autosomal recessive…) To learn more about your specific recurrence risks we recommend that you speak with a genetics professional.

When hypomelanosis of Ito is suspected, careful evaluation with a Wood's lamp may help confirm the diagnosis. Additional genetic testing may be recommended to discover any related medical problems.

Currently there is not a cure for hypomelanosis of Ito. Therapies are aimed at treating the symptoms in the child (e.g., seizures, scoliosis, strabismus). Children with this condition often receive their care from a multidisciplinary team of healthcare providers, including a pediatric ophthalmologist, neurologist, orthopedic specialist and others as needed. The overall prognosis of the child will depend on the severity of the associated symptoms.

The overall prognosis of a child with hypomelanosis of Ito will depend on the severity of the associated symptoms. The life expectancy is normal for symptoms that only involve the skin changes.