Genetic Pigmentary Disorders: From Molecular Mechanisms to Clinical Manifestations

Genetic pigmentary disorders represent a diverse group of genetic conditions characterized by alterations in melanin production and transport and melanocyte development, resulting from single-gene pathological variants. These disorders encompass both hypopigmentary and hyperpigmentary phenotypes, affecting not only skin pigmentation but also ocular, auditory, and systemic manifestations. This review examines the molecular mechanisms underlying major genetic pigmentary disorders, including hypopigmentary (e.g., oculocutaneous albinism, piebaldism, and Waardenburg syndrome) and hyperpigmentary (e.g., dyschromatosis symmetrica hereditaria, dyschromatosis universalis hereditaria, reticulate acropigmentation of Kitamura, and Dowling-Degos disease) disorders. Additionally, we discuss RASopathies, in which pigmentary abnormalities occur alongside multisystem developmental anomalies. Comprehensive understanding of these conditions can provide crucial insights into melanocyte biology and guide future clinical management strategies for affected patients.