Albinism in humans is a congenital disorder inherited from the genes of both parents, which occurs in one out of every 17,000 people in some form. Recessive genes for the condition are more common, with one in 70 people carrying the recessive gene for albinism. Parents carrying the genes usually have normal skin and eye color, but depending on the gene defect the condition can affect the skin, hair, and eyes or primarily the health of the eyes. People with albinism are generally healthy other than having vision problems and skin that is sensitive to the sun, but rare forms and other conditions can lead to exacerbated health issues.
Common forms of albinism in humans are oculocutaneous albinism, in which the hair and skin lack pigmentation, and the eyes are light in color as well. In some cases, the connections of the optic nerve are affected. The eyes are the focus of the condition in rarer forms known as ocular albinism. Skin and hair in affected people in this case might look similar to that of their families or ethnic groups. Albinism in humans is found in different forms which are characterized by the lack of or dysfunction of tyrosinase, an enzyme which regulates melanin pigments.
The causes of albinism in humans are genetic. Both parents need to transmit the gene, which carries genetic material for body characteristics. Even if each parent has the gene, it is not guaranteed that the child will have albinism; the chances are about one in four. The gene for ocular albinism is located on the X chromosome, so this type is most often seen in males. Low vision and lack of pigmentation in the eye affect people with this condition; usually the eyes are blue or green but in rare cases can appear pink when light passes through most of the eye instead of only the pupil.
Albinism in humans often results in no significant health issues, and affected individuals usually live a normal life span. It does not affect hearing or the immune system, but rare associated conditions like Hermansky-Pudlak Syndrome can cause serious lung problems. For most people, albinism can vary in symptoms and in rare cases might not know they have it. Albinism in animals is seen to similar degrees and occurs in birds, fish, frogs, and even deer and raccoons. Though typically it doesn’t affect their health, such animals don’t often live long, especially if they rely on camouflage to hide from predators.
