BỆNH BẠCH TẠNG
Albinism (English: Albinism is derived from Latin: albus meaning "white") is a general term for congenital disorders caused by a disorder in the biosynthesis of the pigment melanin, give the patient's skin, hair, and eyes a light color. The skin of a person with albinism is prone to sunburn, which in turn is prone to skin cancer. In addition, albinism also causes visual disturbances, decreased vision and photophobia.

Albinism occurs in most ethnic groups worldwide at a rate of about 1:200000, most commonly in Africa with more than 1:10000. The pale skin color of Asians and Europeans is type 4 albinism due to a biological mutation in the OCA 4 gene, blond hair and blue eyes are albino due to mutations in the OCA 2 gene and several other genes.

In mammals including humans, albinism presents with pale eyes, skin, hair, or fur. For other groups of animals, besides melanin, there are other pigments, so the expression of albino is not the same. In birds, the blue and green colors are caused by the color combination of feather structures with the pigment melanin. Yellow, orange, and red are usually caused by carotene pigments. The blue, green, silvery or iridescent color in reptiles, amphibians and fish is due to the reflection of light by purines. Yellow, orange and red colors are caused by carotenes and pteridine. All these pigments can be lost due to biological mutations.