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  Indian J Med Microbiol
 

Figure 2: Biosynthetic pathway of melanin. Melanin is present in two main forms: (1) the highly ultraviolet-protective brown/black “eumelanin” pigment, and (2) the ultraviolet-permeable red/blonde “pheomelanin.” Eumelanin and pheomelanin are both synthesized from tyrosine, an amino acid. Tyrosinase, the enzyme that catalyzes the synthetic rate-limiting reaction for both types of melanin, is the deficient enzyme in the most common type of albinism. The incorporation of a cysteine into pheomelanin leads to the retention of a moiety of sulfur into the pigment, which can contribute to oxidative injury caused by ultraviolet. D'Orazio et al.[11] (DOPA: 3,4-dihydroxyphenylalanine, DHI: 5,6-dihydroxyindole, DHICA: 5,6-dihydroxyindole-2-carboxylic acid).

Figure 2: Biosynthetic pathway of melanin. Melanin is present in two main forms: (1) the highly ultraviolet-protective brown/black “eumelanin” pigment, and (2) the ultraviolet-permeable red/blonde “pheomelanin.” Eumelanin and pheomelanin are both synthesized from tyrosine, an amino acid. Tyrosinase, the enzyme that catalyzes the synthetic rate-limiting reaction for both types of melanin, is the deficient enzyme in the most common type of albinism. The incorporation of a cysteine into pheomelanin leads to the retention of a moiety of sulfur into the pigment, which can contribute to oxidative injury caused by ultraviolet. D'Orazio <i>et al</i>.<sup>[11]</sup> (DOPA: 3,4-dihydroxyphenylalanine, DHI: 5,6-dihydroxyindole, DHICA: 5,6-dihydroxyindole-2-carboxylic acid).