What term refers to congenital hypopigmentation or absence of melanin pigment in the body, including skin and hair?

The term that best describes congenital hypopigmentation or the complete absence of melanin pigment in the body, affecting both skin and hair, is albinism. Albinism is a genetic condition caused by a mutation in one of the genes responsible for the production of melanin, the pigment that gives color to the skin, hair, and eyes. Individuals with albinism have a significantly reduced amount of melanin, which leads to very light skin and hair, often accompanied by specific vision problems due to the lack of pigment in the eyes.

In contrast, vitiligo is a condition characterized by the loss of skin pigment in patches due to autoimmune activity, but it is not congenital and affects only certain areas rather than the entire body. Hyperpigmentation refers to darkened areas of the skin caused by excess melanin production, which is the opposite of the lack of pigment seen in albinism. Hypopigmentation is a broader term that refers to any reduction in skin color and does not specifically denote the complete absence of melanin as seen in albinism. Therefore, the specific term that accurately describes the condition of total absence of pigment is albinism.