Synthesis of Melanin and its Disturbances

• Melanin is produced by mature melanocytes. The biosynthesis of melanin is a complex which implicateds numerous enzymes which include tyrosinase, TRP1, TRP2…Genetic disturbances of these enzymes can result in a pigmentary dilution which translates clinically with depigmentation as is seen for example in oculocutaneous albinism.
• The production of melanin is done within melanocytes in organelles called melanosomes.
• The impairement of the migration of the vesicles which aggregate to create these organelles can also lead to a pigmentary dilution such as that seen in Chediak-Higashi syndrome and Hermansky Pudlak syndrome.
• Impaired migration of melanosomes to the dendritic processes of the melanocytes leads to Griscelli syndrome.

Contributors:

Dr Christophe HSU – dermatologist. Geneva, Switzerland

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