What does albinism refer to?

Albinism refers to the absence of melanin pigmentation in the body, which results in lighter skin, hair, and eyes. This genetic condition occurs due to a mutation that affects the production of melanin, the pigment responsible for coloring the skin, hair, and eyes. People with albinism typically have very pale skin and may be more susceptible to sunburn and skin-related health issues due to the lack of melanin, which provides some natural protection from UV rays.

The other options do not accurately describe albinism. Excessive pigmentation in the skin refers to conditions like hyperpigmentation, while partial loss of hair pigmentation would be related to conditions such as graying hair rather than albinism. A skin disease causing patchy pigmentation might refer to vitiligo, which involves the loss of pigmentation in specific areas but does not describe the global lack of melanin seen in albinism. Thus, the absence of melanin pigmentation is the defining characteristic of this condition.