Sickle Cell Disease Inheritance Patterns

How does race/ethnicity affect your risk of sickle cell disease?

The Hb S gene variant in the HBB gene is more common in families that come from Africa, India, Mediterranean countries, the Middle East, the Caribbean islands and South and Central America. In the United States, it most commonly affects African-Americans. Your race/ethnicity influences your likelihood of being a carrier for the Hb S or Hb C variant. There are other HBB gene variants that are more common in other races/ethnicities.

How likely someone of this background is to be a carrier:

African-American

Hb S: 1 in 11 (9%)

Hb C: 1 in 42 (2.4%)

Asian Hb S and Hb C: Almost none (<<1%) Non Hispanic-White Hb S and Hb C: Almost none (<<1%) Ashkenazi Jewish Hb S and Hb C: Almost none (<<1%) Other/Mixed Race No specific data is available.

What role do nongenetic factors play in sickle cell disease?

Nongenetic factors do not play a role in whether someone will develop sickle cell disease because it is caused by gene variants alone. However, nongenetic factors including dehydration, infection, extreme temperatures and stress can increase the likelihood of a sickle cell crisis.

Did you know?

Malaria is a disease spread by mosquitoes. Sickle cell carriers are more likely to survive malaria than non-carriers. Carriers have become more common in places where malaria is prevalent, like African countries near the equator. https://www.mayoclinic.org//-/media/kcms/gbs/patient-consumer/images/2017/09/06/18/08/sicklecelldisease-malariainafrica-1020x475.jpg Learn more Mayoclinic.org Genetics Home Reference