Leucism is a condition characterized by reduced pigmentation in animals and humans. Unlike albinism, it's caused by a reduction in all types of skin pigment, not just melanin. Details Leucism (occasionally spelled leukism) is a general term for the phenotype resulting from defects in pigment cell differentiation and/or migration from the neural crest to skin, hair or feathers during development. This results in either the entire surface (if all pigment cells fail to develop) or patches of bod… (More on Leucism)