Sickle-cell Anemia

Sickle cell anemia is a disease involving abnormally shaped red blood cells, which then have difficulty circulating properly through the body. It is caused by a one <!g>nucleotide substitution in one gene. This is a recessive mutation, meaning that the disease only develops when both copies of the gene (one on each duplicate <!g>chromosome) contain the substitution. Interestingly, people with only one copy of the mutation (who thus have normal red blood cells) show an increased resistance to malaria.

Related Topics:

	Genetics
	Evolution
	Health

Contributed by: <!g>CTNS