Albino and Rare White Animals

Albinism is due to various gene mutations that affect the production of normal pigmentation. True (amelanistic) albinos lack melanin and are white with no markings and with unpigmented pink eyes. Partial (blue-eyed) albinos have some residual pigmentation. There are various degrees of patchy albinism (piebaldism) due to localised mutations in skin cells. Temperature dependent albinos have residual colour on cooler parts of the body i.e. Siamese cats where pigment develops on the head, tail and legs, but not on the warmer parts of the body.

Bluish-grey anerythristic albinos lack the red colour. Axanthic albinos lack the yellow colour. The actual colour and pattern of these animal depends on what other colours are in the pattern. Tyrosinase-negative albinos lack tyrosinase (an enzyme which synthesises melanin) in their cells; this usually produces a pale yellowish or cream animal with pink-eyes. The more common Tyrosinase Positive albino cannot synthesise melanin, but can synthesise tyrosinase, giving a fawn or lavender (platinum) colour.

Leucism is often mistaken for albinism. Leucistic animals, such as white lions, are white or very pale, with dark eyes and some pigmentation, for example ghost markings. Chinchilla is sometimes mistaken for albinism, but is caused by a different mutation that affects the distribution of pigment on the hair shaft. White tigers are chinchilla. Other mutations also cause white animals; some of the animals pictured here (white peacocks) are white, but not albino.