It includes a spectrum of clinical syndromes characterized by hypomelanosis i.e., reduced synthesis of melanin pigment in skin and eyes. The defect is in the enzyme tyrosinase which is responsible for the biosynthesis of the pigment and hence the individual appears bleached. In this condition, melanin is not synthesized in the melanocytes and affects the skin, hair, sclera and choroids etc. Melanin is synthesized from tyrosine as shown in the figure 7.3.
Generally, two types of albinism is seen ; a) Oculo-cutaneous albinism. In this type, there is decreased pigmentation of skin and eyes, b) Ocular albinism. In this type, there is decreased pigmentation of only eyes and not the skin.