Piebaldism

Piebaldism is a rare genetic condition characterized by congenital patches of white skin and hair due to the absence of melanocytes in affected areas. It is most often inherited in an autosomal dominant pattern, though many cases arise from de novo KIT gene mutations. The KIT gene encodes the c-KIT receptor tyrosine kinase, which is essential for the development, migration, and survival of melanocytes.

Clinically, piebaldism is usually evident at birth. The hallmark features include a white forelock of hair and depigmented patches on the trunk and proximal limbs, with relatively spared facial skin. The patches persist throughout life. Vision and hearing are typically normal, and there are no systemic findings.

Pathologically, affected skin shows an absence or marked reduction of melanocytes, while surrounding skin contains normal melanocytes.

Diagnosis is based on clinical examination and the pattern of depigmentation; genetic testing for KIT mutations can confirm the diagnosis. It should be distinguished from vitiligo, which is usually acquired and may involve autoimmune processes, and from Waardenburg syndrome, which may include additional features such as dystopia canthorum or hearing loss.

Management is focused on cosmetic and psychosocial aspects, as there is no cure. Options include camouflage with makeup, dermal pigmentation techniques such as micropigmentation, and, in selected cases, cellular therapies or melanocyte transplantation. Sun protection is advised for depigmented skin.

Prognosis is generally favorable, with normal life expectancy and no impact on overall health, though the cosmetic appearance can be a source of psychosocial concern. Genetic counseling is recommended due to its autosomal dominant inheritance.