Sickle cell anemia is a genetic disease in which the hemoglobin molecules that carry oxygen from the lungs to the body cells are misshapen. This results in these molecules clustering into misshapen red blood cells—instead of cells having the typical biconcave shape, they are sickle-shaped. Sickled cells have reduced oxygen-carrying capability, and generally have much shorter life spans than normal red blood cells, leading to anemia, or systemic deficiency in red blood cell function and concentration.
Protein Coding
Hemoglobin is a protein, or large biological molecule made up of a long chain of smaller molecules called amino acids. There are 20 different types of amino acids, and these can be strung together in various combinations to produce chains of different lengths. Every protein is made up of amino acids, but the length of the chain and the identities of the amino acids determines the type and functionality of the protein. Sickle cell anemia results from a mistake in the order of amino acids strung together to form the hemoglobin protein, note biochemists Mary Campbell and Shawn Farrell. While the mistake appears small—just one wrong amino acid out of 146—it’s sufficient to throw off the entire function of the hemoglobin protein, and causes the protein to behave in abnormal ways, including clustering to form sickled, rather than biconcave, red blood cells.
Pain
One of the abnormal traits displayed by sickled red blood cells is that instead of slipping past one another in the small blood vessels of the organs and extremities, they tend to stick and form large clusters. These clusters can act like blood clots, preventing the passage of blood and preventing cells beyond the cluster from receiving oxygen and nutrients. This leads to cell and organ damage, and can cause severe pain, notes MayoClinic.com. Sickle cell pain episodes can vary in intensity and duration, and may require hospitalization for administration of pain medicine.
Oxygen Debt
The National Heart Lung and Blood Institute notes that anemia is responsible for a host of traits of sickle cell anemia patients, simply because the job of red blood cells is such an important one. Body cells can’t function without oxygen—in its absence, they’re unable to burn fuels for energy to any significant degree—so limited red blood cell number and functionality severely limits the ability of a sickle cell patient to engage in physical activity. Patients often feel fatigued, short of breath, and may have chest pain or dizziness. Further, cool or blanched extremities are indicators that the hands and feet aren’t receiving adequate oxygenation.
References
- “Biochemistry”; Mary Campbell, Ph.D. and Shawn Farrell, Ph.D.; 2005
- MayoClinic.com: Sickle Cell Traits
- National Heart Lung and Blood Institute: Sickle Cell Traits
