Migration of Melanocytes during Melanogenesis

• Melanocytes originate from the neural crest. During early embryogenesis, melanocyte precursors migrate from the neural crest to the epidermis in a dorsolateral fashion. This migration is also done to the internal ear.
• This migration pathway and the maturation of the melanoblasts are regulated by a variety of factors, which included tyrosinase receptors such as c-kit.
• Mutations of genes which contraol this pathway induce localized depigmentation and leukkotrichia as in Waardenburg Syndrome and Piedbaldism. In these 2 disorders, hearing and colonic function are also impaired

  

  Brothers with Waardenburg syndrrome (Synonyms: Waardenburg­ Shah syndrome, Waardenburg-Klein syndrome, Mende II syndrome, Van der Hoeve-Halbertsma-Waardenburg syndrome, Ptosis-Epicanthus syndrome, Van der Hoeve-Halbertsma-Gualdi syndrome, Waardenburg type Pierpont, Van der Hoeve-Waardenburg-Klein syndrome, Waardenburg II syndrome and Vogt syndrome).

• The migration of melanocytes is halted in the dermis in disorders uch as Mongoloid Spots, nevus of Ota, Nevus of Ito and nevus of Hori.

Contributors:

Dr Christophe HSU – dermatologist. Geneva, Switzerland

Source of information: Goh BK. The Science Behind Pigmentary Disorders. NSC Dermatology Update 2012, Singapore