1. Sickle Cell Inheritance
Exploring Genetics and Probability

2. What is sickle cell?
Sickle cell is a genetic condition that causes the red protein in blood (hemoglobin) to make the blood cells rigid and pointy.
The gene for sickle trait is spread throughout the world.
It was most common in the areas where there was a lot of malaria because sickle trait actually helps people survive malaria.

3. What is sickle trait?
In order to inherit anything from your parents, you get one gene from each parent.
The way sickle cell disease occurs is if you get a sickle gene from both your parents.
If you only get one sickle gene and your other gene is normal, you have sickle trait.

4. Health Benefit of Sickle Trait
Protects against risk of death from malaria infection.
Malaria kills thousands of kids a year.
Note: only sickle trait gives protection against the deadly strains of malaria

5. More on Malaria Caused by a parasite that can live in mosquitoes
Parasites infect red blood cells
Symptoms include fever, vomiting, headache
Can cut off blood supply to vital organs
Different strains of malaria, some are deadly
Children are very susceptible to dying of malaria

6. Myth vs Reality Myth: Only African Americans get sickle cell.
Reality: Sickle cell affects people of all different racial and ethnic backgrounds.
African, Arabian, Israeli, Turkish, Pakistani
Greek, Hispanic, Italian
Blond hair/blue eyed children of Northern Europe
One case in Hong Kong!

7. Where do people have sickle cell?
Highest frequency in Sub-Saharan Africa
Also prevalent across the US, on the Atlantic side of Central and South America, the Caribbean, Europe, North and Central Africa, the Middle East and South Asia.

8. Map from Dr. Lewis Hsu, MD, PhD,
Professor of Pediatrics,
Director of Pediatric Sickle Cell, University of Illinois, Chicago, IL

9. Inheriting a sickle gene
This is a genetic condition, so whether somebody gets sickle cell disease or sickle trait depends completely on what genes you get from your parents.

10. A S – Sickle trait S S – Sickle Cell Disease A A – Normal
The Inheritance Game
A S – Sickle trait S S – Sickle Cell Disease A A – Normal

11. A A A S S S A S A S Modeling inheritance Mother’s genes Sickle trait
Normal
A S
Sickle trait
S S
Sickle cell disease
Father’s genes

12. Acknowledgements Adapted from ideas by
Camille Coleman, Genetic Counselor, Marian Anderson Comprehensive Sickle Cell Center, St. Christopher’s Hospital for Children, Philadelphia, PA
Lewis Hsu, MD, PhD, Professor of Pediatrics, Director of Pediatric Sickle Cell, University of Illinois, Chicago, IL
Rebecca Hui, 4th Grade Teacher, St. Frances of Rome School, Chicago, IL

13. References and Related Resources
Center for Disease Control
Sickle Cell Information Center