Sickle-cell disease overview
|
Sickle-cell disease Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Sickle-cell disease overview On the Web |
|
American Roentgen Ray Society Images of Sickle-cell disease overview |
|
Risk calculators and risk factors for Sickle-cell disease overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aarti Narayan, M.B.B.S [2]
Overview
Sickle-cell disease is a group of genetic disorders caused by sickle hemoglobin (Hgb S or Hb S). In many forms of the disease, the red blood cells change shape upon deoxygenation because of polymerization of the abnormal sickle hemoglobin, the hemoglobin sticks to each other, causing the cell to get a rigid surface and sickle shape. This process damages the red blood cell membrane, and can cause the cells to become stuck in blood vessels. This deprives the downstream tissues of oxygen and causes ischemia and infarction, which may cause organ damage, such as stroke. The disease is chronic and lifelong. Individuals are most often well, but their lives are punctuated by periodic painful attacks. Life-expectancy is shortened, but contemporary survival data is lacking. Older studies indicated that sufferers could live to an average of 40 to 50 years, with the average age for males being 42 and the average age for females being 48. Sickle-cell disease occurs more commonly in people (or their descendants) from parts of the world such as sub-Saharan Africa, where malaria is or was common, but it also occurs in people of other ethnicities. As a result, those with sickle cell disease are resistant to malaria since the red blood cells are not conducive to the parasites. The mutated allele is recessive, meaning it must be inherited from each parent for the individual to have the disease.