Sickle Cell Disease

What is Sickle Cell Disease? Affects millions around the world, mostly in Africa About 70,000 Americans are estimated to have the disease About 1000 babies are born with the disease in the US each year

What is Sickle Cell Disease? Sickle cell is passed on by a recessive gene People with only one copy of the gene are healthy Since they can still pass on the recessive sickle-cell gene, these people are called “carriers” Sickle cell gene in blue… Can be covered up by the dominant gene (red).

What is Sickle Cell Disease? People with two copies of the sickle cell gene have sickle cell disease If two people who are both carriers have children, what is the possibility of their child having sickle cell disease? Set up a Punnett square to figure this out! (H is the healthy gene, h is the sickle cell gene) + = sickle cell disease

Punnett Square H h H h HH Hh Hh hh “Carriers” are heterozygous (they have one dominant gene and one recessive gene) H h There is a 25% chance that their child will have the sickle cell disease. H h HH Hh Hh hh

What does it do to you? People with two copies of the sickle cell gene have sickle cell disease The gene codes for hemoglobin, an important protein in red blood cells The abnormal form of hemoglobin clumps together, which changes the shape of the red blood cells + = sickle cell disease

What does it do to you? Sickled cells are fragile, sticky, and stiff These cells can get trapped in blood vessels, making it impossible for blood to get through Muscles and organs that depend on blood for oxygen and nutrients can suffer or even stop working

Why is it still around? If sickle cell disease is so bad, why does the trait still exist in such high numbers? Watch this video.(8 min)