Pigment Genodermatoses Affecting Melanocyte Development and Migration from the Neural Crest: Piebaldism, Waardenburg Syndrome and Cross-McKusick-Breen Syndrome

Piebaldism, Waardenburg syndrome and Cross-McKusick-Breen syndrome are rare disorders characterized by congenital skin and hair hypopigmentation. Piebaldism is inherited in an autosomal dominant pattern and Waardenburg syndrome is mostly transmitted in an autosomal dominant manner. These diseases are caused by abnormal migration of melanoblasts from the neuroectoderm into the skin. Cross-McKusick-Breen syndrome is an autosomal recessive disorder in which the epidermal melanocyte numbers are normal, but most melanosomes are in stage II or III and are probably characterized by defective melanosomal transfer. This publication describes the clinical and genetic characteristics of the three selected genodermatoses. Although rare and phenotypically diverse, the study of these diseases has yielded significant knowledge on the genes that regulate the migration of melanocytes and the mechanisms that control skin, hair and eye pigmentation.