Ads
related to: heterozygous sickle cells
Search results
Results From The WOW.Com Content Network
Sickle cell trait describes a condition in which a person has one abnormal allele of the hemoglobin beta gene (is heterozygous), but does not display the severe symptoms of sickle cell disease that occur in a person who has two copies of that allele (is homozygous).
Sickle cell disease (SCD), also simply called sickle cell, is a group of hemoglobin-related blood disorders typically inherited. The most common type is known as sickle cell anemia. It results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells.
A well-established case of heterozygote advantage is that of the gene involved in sickle cell anaemia. Often, the advantages and disadvantages conveyed are rather complicated, because more than one gene may influence a given trait or morph .
While malaria is still affecting the regular cells (2), the ratio of sickle to regular cells is 50/50 due to sickle cell anemia being a heterozygous trait, so the malaria cannot affect enough cells with schizonts (5) to harm the body.
Sickle cell-beta thalassemia is caused by inheritance of a sickle cell allele from one parent and a beta thalassemia allele from the other. Mutations. A sickle allele is always the same mutation of the beta-globin gene (glutamic acid to valine at amino acid six). In contrast, beta-thalassemia alleles can be created by many different mutations ...
It also reports the genetic basis for the disease, consistent with the simultaneous genealogical study by James V. Neel: those with sickle-cell anemia are homozygous for the disease gene, while heterozygous individuals exhibit the usually asymptomatic condition of sickle cell trait.
Heterozygous AE occurs when the gene for hemoglobin E is inherited from one parent and the gene for hemoglobin A from the other. This is called hemoglobin E trait, and it is not a disease. People who have hemoglobin E trait (heterozygous) are asymptomatic and their state does not usually result in health problems.
This is an example of balancing selection between the fierce selection against homozygous sickle-cell sufferers, and the selection against the standard HgbA homozygotes by malaria. The heterozygote has a permanent advantage (a higher fitness) wherever malaria exists.
Compound heterozygosity. In medical genetics, compound heterozygosity is the condition of having two or more heterogeneous recessive alleles at a particular locus that can cause genetic disease in a heterozygous state; that is, an organism is a compound heterozygote when it has two recessive alleles for the same gene, but with those two alleles ...
Hemoglobin variants are a part of the normal embryonic and fetal development. They may also be pathologic mutant forms of hemoglobin in a population, caused by variations in genetics. Some well-known hemoglobin variants, such as sickle-cell anemia, are responsible for diseases and are considered hemoglobinopathies.
Ad
related to: heterozygous sickle cells