Albinism in humans is birth defect characterized by the complete or partial absence of pigment in the skin, hair and eyes. Albinism results from inheritance of recessive gene alleles. It is due to absence or defect of a gene involved in the production of melanin.
Albinism is caused by a mutation in one of several genes. The genes in question are responsible for various aspects of the production of melanin by melanocytes in the skin and eyes.
Most commonly, the mutations interfere with the enzyme tyrosinase (tyrosine 3-monooxygenase) which synthesizes melanin from the amino acid tyrosine.
Depending on the mutation, melanin production can either be slowed or completely stopped. But, regardless of the amount of interference with melanin production, there are always associated problems with the visual system in albinism.
These vision problems occur because of melanin’s vital role in the development of the retina and the optic nerve pathways from the eye to the brain.