Ask Our Experts
Get answers to your specific medical questions from UM Medical Center experts.
Related Content
Sickle cell disease
Description
An in-depth report on the causes, diagnosis, and treatment of sickle cell disease.
Alternative Names
Sickle cell anemia
Risk Factors
Sickle cell disease is inherited. People at risk for inheriting the gene for sickle cell descend from people who are or were originally from Africa and parts of India and the Mediterranean. The sickle cell gene also occurs in people from South and Central America, the Caribbean, and the Middle East. The high incidence of the sickle cell gene in these regions of the world is due to the sickle cell's ability to make red blood cells resistant to the malaria parasite:
- People who inherit just a single gene are referred to as having the sickle trait . These people are protected against malaria and do not develop sickle cell disease. About 40% of people in certain parts of Africa and about 9% of African-Americans have the trait.
- Those who inherit both copies of the HbS gene develop sickle cell disease. They are not protected from malaria, however. In fact, malaria is more serious in these individuals. An estimated 1 in 500 African-Americans and 1 in 1,000 - 1,400 Hispanic Americans are born with sickle cell disease.
Risk in Children of Parents with the Sickle Cell Gene
The sickle cell gene for hemoglobin S (HbS) is the most common inherited blood condition in America. About 72,000 Americans -- mostly African-Americans -- have sickle cell disease. The risk for inheriting sickle cell disease from parents with the sickle cell gene is as follows:
- One parent has only one copy of the sickle cell gene and the other parent has two normal hemoglobin genes, and the child inherits a healthy gene from each parent. The child will not inherit either the disease or the trait.
- The child inherits one copy of the sickle cell gene. The child has the trait (HbS) only. The other, healthy hemoglobin gene overrides HbS and blocks the development of sickle cell disease. Such people lead normal lives.
- The child inherits the hemoglobin S gene from both parents (HbSS). The child develops the full-blown disease. (If each parent has one copy of the gene, the child has a 25% chance of acquiring the disease.)
- The child inherits one hemoglobin S gene and one abnormal hemoglobin gene from other causes (such as one form called HbSC). Such children may develop a form of sickle cell disease. It is often a milder variant but children can experience severe symptoms. They are also at risk for some of the complications of sickle cell disease, although their risks for serious problems are lower than in children with the full-blown disease.
- Review Date: 1/17/2007
- Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital
|
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process . A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch). |
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
Email this Page
Print this Page