Explanation:
Surprisingly, until recently, not much was known about the genes that control melanin production. 6 were known (MC1R, TYR, OCA2, SLC24A5, MATP and ASIP) and 17 more have been recently identified (DTNBP1, GPR143, HPS3, KITGL, MLPH, MYO5A, MYO7A, SLC45A2, TYRP1, ERCC6, GNAS, HERC2, IRF4, OBSCN, SKC24A5, TPNC2 and MITF), all of them directly or indirectly related to the process of melanin formation and distribution. Since there are so many different genes, if we count all the possible alterations, many different color variants can be produced.
