Search results
Results from the WOW.Com Content Network
Sickle-cell anemia (SCA) is a genetic disorder caused by the presence of two incompletely recessive alleles. When a sufferer's red blood cells are exposed to low-oxygen conditions, the cells lose their healthy round shape and become sickle-shaped. This deformation of the cells can cause them to become lodged in capillaries, depriving other ...
A well-studied case is that of sickle cell anemia in humans, a hereditary disease that damages red blood cells. Sickle cell anemia is caused by the inheritance of an allele (HgbS) of the hemoglobin gene from both parents. In such individuals, the hemoglobin in red blood cells is extremely sensitive to oxygen deprivation, which results in ...
Sickle cell disease (SCD), also simply called sickle cell, is a group of hemoglobin-related blood disorders that are typically inherited. [2] The most common type is known as sickle cell anemia. [2] Sickle cell anemia results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells. [2]
Sickle-cell disease and the associated trait are most prevalent in Africa and Central America, which is attributed to natural selection: the sickle-cell trait confers a survival advantage in areas with a high occurrence of malaria, which has a high death rate among individuals without the trait. [citation needed]
Having a sickle-cell allele does limit the life expectancy of a person, however, the presence of sickle-cell genes reduces the detrimental effects of malaria should it be contracted. Natural selection allowed for the spreading of the sickle-cell gene in areas of high numbers of mosquitoes carrying malaria; those that weren't as susceptible to ...
Natural selection is the differential survival and ... of which the best-known example is the resistance to malaria in humans heterozygous for sickle-cell ...
Overdominance is a phenomenon in genetics where the phenotype of the heterozygote lies outside the phenotypical range of both homozygous parents. Overdominance can also be described as heterozygote advantage regulated by a single genomic locus, wherein heterozygous individuals have a higher fitness than homozygous individuals.
Sickle-cell disease was the genetic disorder to be linked to a mutation of a specific protein. Pauling introduced his fundamentally important concept of sickle cell anemia as a genetically transmitted molecular disease. [20] This vein (4) shows the interaction between the malaria sporozoites (6) with sickle cells (3) and regular cells (1).