An example of point-mutation is sickle-cell anemia. Sickle-cell disease is hereditary.

The word is falcate. It means curved like a sickle.

Sickle cell disease is a group of disorders that affects molecule in red blood cells (hemoglobin) that delivers oxygen to cells throughout the body. Person with this disorder have typical hemoglobin molecules called hemoglobin S, which can distort red blood cells into a sickle, or crescent, shape.

autoimmune disease

No, sickle cell anemia is a disease of the hemocytes, the red blood cells. Leucocytes are one type of white blood cell.