piebaldismi

Piebaldism is a rare, congenital genetic condition characterized by patches of depigmented skin and hair, most notably a white forelock. The depigmented areas are present at birth and tend to be stable over time. Unlike some other pigmentary disorders, piebaldism is non-progressive and not autoimmune.

Most cases result from heterozygous loss-of-function mutations in the KIT gene, which encodes a receptor tyrosine kinase essential for the development and survival of melanocytes. The condition is usually inherited in an autosomal dominant manner, though de novo mutations occur; penetrance is high with variable expressivity.

Clinical features typically include depigmented patches on the trunk and limbs, often sparing the midline, and a conspicuous white forelock of hair. Facial involvement can occur. Patches do not tan and are usually present from birth. Ocular and systemic function are generally normal.

Diagnosis is based on clinical presentation, with Wood lamp examination helping to delineate depigmented areas. Genetic testing for KIT mutations can confirm the diagnosis and assist with counseling. The main differential diagnoses are vitiligo, which is usually acquired and may have an autoimmune basis, and albinism, which tends to involve broader and more systemic pigmentary and ocular changes.

Management has no cure and is focused on protection from sun exposure and cosmetic options. Options include camouflage makeup or, in some centers, cosmetic or surgical pigment restoration techniques, though these are not widely standard. Genetic counseling is advised. Piebaldism is typically non-progressive with normal overall health, though cosmetic and psychosocial considerations may affect quality of life.