Leucism vs Albinism

The terms leucistic and leucism are used in the medical field. The first part leuc- is the Latin variant of leuk- from the Greek leukos meaning "white". Albino derive from Latin albus or alba via Spanish and Portuguese albo or alba, which also mean "white". Albinism is also sometimes referred to as being hypomelanistic or hypomelanism.

Albinism which is considered a disease results from inheritance of recessive alleles and is caused by a reduction in all types of skin pigment, not just melanin. Leucism on the other hand is a condition characterized by reduced pigmentation in animals. Leucism is a general medical term for the observable characteristic, resulting from defects in pigment cell of the skin, hair or feathers during development of an organism. This results in either the entire surface or partial areas of body surface having a lack of cells capable of making pigment.

People often confuse leucism with albinism. Since all pigment cell-types differentiate from the same multipotent precursor cell-type, leucism can cause the reduction in all types of pigment, not only melanin. Albinism is a result in the reduction of melanin production only and are not entirely white, but instead display a pale yellow colour. Remember also that white lions are not a result of albinism but instead is caused by a recessive gene. More common than a complete absence of pigment cells is localized or incomplete hypopigmentation that result in irregular patches of white on an animal that otherwise has normal colouring and patterning which is partial leucism and is known as a "pied" effect.

A further difference between albinism and leucism is in eye colour. Due to the lack of melanin production in both the retinal pigmented epithelium and iris, albinos typically have red eyes due to the underlying blood vessels showing through. In contrast, leucistic animals have the colour eyes that they normally would have. Abinistic birds will normally also show some pink legs and a red bill.

By Ferdie Muller