Difference between revisions of "Sickle cell disease"
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| − | '''Sickle cell disease''' is a genetic blood disease seen most commonly in people of [[Africa]]n ancestry. | + | '''Sickle cell disease''' ('''sickle cell anemia''') is a genetic blood disease seen most commonly in people of [[Africa]]n ancestry. Sufferers are chronically [[anemic]] and experience significant damage to their heart, lungs, and kidneys. Cells affected by the disease take on a sickle shape (that is, shaped like a "C"). |
| − | Sickle cell disease is determined by inheriting two recessive [[ | + | Normal red [[blood]] cells are smooth and round like a doughnut without a hole. They move easily through [[blood vessel]]s to carry oxygen to all parts of the body. Sickle-shaped cells don't move easily through blood. They're stiff and sticky and tend to form clumps and get stuck in blood vessels. |
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| + | The clumps of sickle cells block blood flow in the blood vessels that lead to the limbs and organs. Blocked blood vessels can cause pain, serious infections, and organ damage. | ||
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| + | ==Cause== | ||
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| + | The disorder is caused by a genetic defect which causes the blood protein [[hemoglobin]] to form improperly, making it difficult for [[oxygen]] to join with it and be carried through the blood from the lungs to other parts of the body. The specific cause is when the [[gene]] which creates hemoglobin has a single [[base pair]] change, which causes individual hemoglobin proteins to clump together, impairing [[oxidation]]. | ||
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| + | As a result of this [[mutation]], the [[red blood cell]]s tend to take on a sickle shape, rather than their characteristic donut shape. | ||
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| + | Sickle cell disease in a child is determined by inheriting two recessive [[allele]]s from the parents which code for hemoglobin. If a person inherits one [[dominant]] and one [[recessive]] allele (i.e., he is [[heterozygous]]), he is not affected by the disease, but rather benefits from a [[resistance]] to [[malaria]]. Inheritance of two dominant alleles, of course, causes neither the disease nor any resistance to malaria. | ||
== Sources == | == Sources == | ||
| − | http://www.genome.gov/glossary.cfm?key=sickle%20cell%20disease | + | * [http://www.genome.gov/glossary.cfm?key=sickle%20cell%20disease Genome.gov] |
| + | * [http://www.nhlbi.nih.gov/health/dci/Browse/Blood.html NIH Glossary] | ||
[[Category:Diseases]] | [[Category:Diseases]] | ||
Latest revision as of 18:58, November 10, 2012
Sickle cell disease (sickle cell anemia) is a genetic blood disease seen most commonly in people of African ancestry. Sufferers are chronically anemic and experience significant damage to their heart, lungs, and kidneys. Cells affected by the disease take on a sickle shape (that is, shaped like a "C").
Normal red blood cells are smooth and round like a doughnut without a hole. They move easily through blood vessels to carry oxygen to all parts of the body. Sickle-shaped cells don't move easily through blood. They're stiff and sticky and tend to form clumps and get stuck in blood vessels.
The clumps of sickle cells block blood flow in the blood vessels that lead to the limbs and organs. Blocked blood vessels can cause pain, serious infections, and organ damage.
Cause
The disorder is caused by a genetic defect which causes the blood protein hemoglobin to form improperly, making it difficult for oxygen to join with it and be carried through the blood from the lungs to other parts of the body. The specific cause is when the gene which creates hemoglobin has a single base pair change, which causes individual hemoglobin proteins to clump together, impairing oxidation.
As a result of this mutation, the red blood cells tend to take on a sickle shape, rather than their characteristic donut shape.
Sickle cell disease in a child is determined by inheriting two recessive alleles from the parents which code for hemoglobin. If a person inherits one dominant and one recessive allele (i.e., he is heterozygous), he is not affected by the disease, but rather benefits from a resistance to malaria. Inheritance of two dominant alleles, of course, causes neither the disease nor any resistance to malaria.