Albinism is an inherited disorder of melanin production that leads to hypopigmentation (pigment deficiency) of the skin, hair and eyes. Melanin is the name for a group of pigments that determine the color of the skin, eyes and hair, and are produced by cells called melanocytes. Albinism has 1 in 20,000 people worldwide.
What is albinism?
Albinism is a rare genetic disorder that results in a lack of melanin that can be complete or partial, but affects all parts of the hair and skin. As a result, people with this disorder are more sensitive to sun exposure and at higher risk for developing sunburn and skin cancer.
It also affects the eyes and is associated with vision problems (vision impairment, acuity problems). Apart from protection from sunlight, there is no cure for albinism.

Types of albinism
Albinism is divided into several types, some of which are divided into subtypes.
The two basic types of albinism are:
oculocutaneous albinism - affects the skin, eyes and hair,
ocular (eye) albinism - can occur without skin involvement.
Oculocutaneous albinism
Oculocutaneous albinism (OKA) affects the eyes, skin and hair, and is divided into four basic subtypes:
albinism type I,
albinism type II,
albinism type III,
albinism type IV.
Albinism type I (type I EYE)
This type of albinism is due to the absence (OKA1A) or reduced (OKA1B) activity of the enzyme tyrosinase. Namely, in melanocytes, melanin is produced by oxidation of the amino acid tyrosine, and the enzyme tyrosinase is necessary for this process.
There are two subtypes of OKA1:
OKA1A type - no enzyme activity, so there is no melanin production. The skin and hair are milky white, and the eyes are blue-gray. Sunburn often occurs and vision is impaired and strabismus is present. This type makes up 40% of all EYES.
OKA1B type - the activity of the enzyme is reduced, consequently the production of melanin, but it is still present in small quantities. The skin is yellow-reddish, and the symptoms related to vision are less pronounced.
Albinism type II (type II OKA)
Albinism type II makes up 50% of all EYES. Unlike type I, here the activity of the enzyme tyrosinase is normal. There is a wide range of subtypes with a lack of pigment, from minimal to moderate, and skin and hair colors (light blue, yellow) vary. When exposed to the sun, pigmented nevi (moles) and freckles can appear that can become large and dark.
Albinism type III (type III OKA)
OKA3 is present only in the black race. The skin is brown / reddish-brown and the hair is reddish (reddish).
Albinism type IV (type IV EYE)
Type IV is an extremely rare form of albinism. The activity of the enzyme tyrosinase is normal, but the protein responsible for transport across the membrane is involved. The clinical picture is similar to that in type II.
Ocular albinism (OA)
Ocular albinism affects only the eyes.
Given the pattern of inheritance, there are two types of OA:
autosomal recessive OA: occurs in both sexes;
OA linked to the X chromosome: mothers carry the gene and pass it on to their sons, so it only occurs in men.
Ocular albinism with reduced retinal pigmentation. OA can be suspected when parents notice that the child has rhythmic automatic eye movements (nystagmus).
During further diagnostic processing, the following is determined:
passage of light through the iris of the eye (transillumination),
eyes that do not look in the same direction and the inability to focus on the same point (strabismus, wideness),
poor development of the central retina (feveal hypoplasia),
absence of melanin in the eye,
reduced visual acuity,
enhanced sensitivity to light.

Causes of albinism
The causes depend on the type of albinism as already mentioned in the article. The complete deficiency or decreased activity of the enzyme tyrosinase resulting in the absence or deficiency of melanin has been best investigated.
Albinism - inheritance
Different types of albinism have
different types of inheritance.
Oculocutaneous albinism - is inherited in an autosomal recessive manner, ie both parents should have a gene that carries albinism. Even in this case, the chances of children having albinism are 25% and of being gene carriers 50%.
Ocular albinism - autosomal recessive (both sexes are affected) or linked to the X chromosome. In the last form of inheritance, mothers only carry the gene and pass it on to their sons, so only men are affected. A man who has albinism will not have children with albinism, but all female children will be gene carriers and have a 50% chance that their male child has albinism.
Albinism - symptoms
Symptoms of albinism most commonly occur on the skin, hair, and eyes or in isolation on the eyes (ocular albinism).
Symptoms of skin albinism
The most common recognition of albinism is manifested in very light skin and almost white hair. However, the color can vary up to light brown.
Symptoms of hair albinism
Hair color in albinism is usually white or very light. However, yellow, reddish or light brown hair color can also appear.
Symptoms of albinism in the eyes
In albinism, which affects the eyes, the symptoms are manifested in the lack of pigment in the iris, ie the iris looks almost transparent and the eyes are blue-gray.
Treatment of albinism
There is no cure for albinism, but its symptoms (such as impaired vision) can be controlled and damage can be prevented by responsible behavior. It is recommended:
perform regular check-ups with an ophthalmologist,
use of creams with a high SPF sun protection factor (50+),
controlled sun exposure to avoid sunburn and skin cancer,
wear protective clothing that includes long sleeves, long pants and head protection,
wear goggles with a UV filter.
Certain vision and eye disorders can be corrected with some surgical procedures.

Albinism in animals
Every animal produces melanin and may have albinism. As with humans, albinism in animals is rare. Mostly animals that have albinism are excommunicated and separated from the community due to diversity.
Albino animals have characteristic pink or red eyes because the lack of pigment causes the visibility of the veins. They also have a reduced chance of survival, especially when it comes to species that camouflage or that require greater UV protection (such as alligators).