ANTH 110 Lecture Notes - Lecture 4: Balancing Selection, Sickle-Cell Disease, Anemia
Document Summary
Sickle-cell anemia: a condition in which red blood cells assume a crescent. 9sickle) shape when deprived of oxygen, instead of the normal (disk) shape. The sickle-shaped red blood cells do not more through the body as readily as normal cells, and thus cause damage to the heart, lungs, brain, and other vital organs. Sickle-cell anemia is caused by a variant form of the genetic instructions for hemoglobin, the protein that carries oxygen in the red blood cells. Individuals who have sickle-cell anemia have inherited the same allele (hb^s) from both parents are therefor homozygous for the gene (hb^s. Individuals who receive this allele from only one parent are heterozygous (hb^a or hb^s or (hb^as) they have one normal (hb^a) and one sickled (hb^s) allele. Heterozygous generally will not show the full-blown symptoms of the sickle-cell disease (cid:894)(cid:373)ay ha(cid:448)e a (cid:373)ild a(cid:374)e(cid:373)ia a(cid:374)d are (cid:862)carriers(cid:863)(cid:895)
