Albino Miniature Horse

Albino Miniature Horses

Vets define an albino as having a rare generic condition resulting in a miniature horse with no melanin, and hence little or no pigmentation.

The site www.albinism.org says that there is no single albino gene and that albinism is a "group of inherited conditions", with different eye colors:

"A common myth is that by definition people with albinism have red eyes. In fact there are different types of albinism, and the amount of pigment in the eyes varies. Although some individuals with albinism have reddish or violet eyes, most have blue eyes. Some have hazel or brown eyes."

Based on DNA research at the National Organization for Albinism and Hypopigmentation (NOAH), Perlino and Cremello miniature horses (Cream colors), Maximum Sabino and the American Creme Horse (and American White Horse) breeds, are "Type 2" (oculocutaneous albinism) albino horses:

"Type 1 albinism (also called tyrosinase-related albinism) is the type involving almost no pigmentation. Type 1 albinism results from a genetic defect in an enzyme called tyrosinase. This enzyme helps the body to change the amino acid tyrosine into pigment. (An amino acid is a "building block" of protein, and comes from protein in the diet.) Type 2, a type with slight pigmentation, results from a defect in a different gene called the "P" gene."

According to this NOAH page, cream-colored albino humans (with pink skin and pigmentation in the eyes) may have a genetic relationship to the Cremello albino miniature horses:

"In less pigmented types of oculocutaneous albinism, (the type of albinism that affects both the skin and the eyes), hair and skin are cream-colored."

According to the University of Minnesota Computational Biology Center, the Cream-colored pigmentation of some albino humans (OCA1A and OCA1B types) parallels that of albino miniature horses:

OCA1A - "Individuals with OCA1A or the classic tyrosinase-negative OCA are unable to make melanin in their skin, hair or eyes, because they have no active tyrosinase enzyme. They are born with white hair and skin and blue eyes, and there is no change as they mature into teenagers and adults."

OCA1B - "All variations of OCA1B are characterized by having very little or no pigment present at birth followed by the development of varying amounts of melanin in the hair and the skin in the first or second decade. In some cases, the melanin develops within the first year. The hair color changes to light yellow, light blond or golden blond first, and may eventually turn dark blond or brown in the adolescent and the adult."

In miniature horses, it appears that DNA research confirms that the "double-dilute albino horses" include the following colors of miniature horses as "type 2, OCA1B" albino horses:

While not the "true" albino horse that always has pink eyes and is highly sensitive to sunlight, the type-2 albino miniature horses match the the DNA research cited by NOAH.

The "true" albino (with no pigmentation present, including the characteristic pink eyes) is called Tyrosinase Related Oculocutaneous Albinism.

Any animal may be albino, including cold-blooded animals, and equine albinism is indeed present in the miniature horse. It is not true that the "Lethal White Overo" (LWO) syndrome, (a pseudo-albino gene) prevents an albino horse from surviving. The lethal white gene is associated primarily with Overo horses, and LWO is a totally unrelated genetic mechanism from albino genes. There are two types of albinos, homozygous recessive albino and heterozygous recessive albino.

Albino mammals in nature are quite rare. For example, only one albino Gorilla in known to exist. According to notes at James Cook University, Albinism in humans varies varies by race, with 1 in 38,000 whites and about 1 in 22,000 blacks inheriting the Albino gene. Albinism are varies by geography, with Tasmania and Northeastern America having a statistically significant higher incidence of Albino human births.

Some estimate the probability in nature to be more than one in a million. For example, there is a stuffed Albino Beaver in the Anchorage Alaska airport.

True Albino Miniature Horses

There is lots of antidotal evidence that "true" pink-eyed albino horses have existed. According to medicine-book.com, some people claim to have had albino horses:

"in the 1940s a white filly was born with pink eyes. They named her "Sally" and she had no problems physically, she could pull a plow just as well as her parents."

There are photos of albino equines. Here is a photograph of an albino Zebra:

According to Michael Kantner's web site:

"This picture, taken at the Kronberg zoo in Germany, was found in a Soviet magazine and supplied by Askar Isabekov."

According to the Western Producer, there may have been true albino horses:

"However, equine veterinarian Ross McKague of Brandon said the lack of documented cases does not mean true albino horses never existed. It was only in recent times that technology reached the point where the genes behind that trait could be identified, he added, which would make it easier to determine whether a horse was a true albino."

While exceeding rare (no known photographs exist) there is no reason that the recessive "true" albino trait cannot exist in miniature horses.