sickle cell inheritance (2023)

“Those who can get there and speak for them are the only ones, the thousands, who carry the disease, the trait. It's important for the trait community to speak. And that's how wefight this thing.

—Joyce, madam

genesthey usually come in pairs: one copy of a gene comes from each biological parent. This pair of genes is known asgenotype. Sickle cell disease is caused by the inheritance of two copies (one from each parent) of aHBBgene, which causes the production of an abnormal form of beta (β)-globin, such ashemoglobina S (HbS). Scientists have identified hundreds of variations in theHBBgene that causes abnormal beta globin to form and cause disease. As a result, there is more than one type of sickle cell disease, depending on the specific combination of changes in theHBBgene you inherit These different forms are described as their sickle cell genotype.

Inheritance Determination Tool

Use the interactive diagram below, called a Punnett square, to see the probability that a child will inherit a form of sickle cell disease or sickle cell trait. This Punnett square can help you see how genes can be passed from parent to child.in each pregnancy, regardless of the genotypes of the previous offspring. Please note that the “sickle cell disease” selection for this tool is for the most common type of sickle cell disease, hemoglobin SS. However, you can create your own Punnett square by following the format below and using a different genotype (such as hemoglobin SC or beta-zero hemoglobin S) in place of "SS".

Select a genotype (i.e., AA, without sickle cell disease; AS, carrier of sickle cell trait; or SS, sickle cell disease) for both sexes, then select "View Results" to see the chances that a child inherited sickle cell disease. or disease

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Without sickle cell disease

As mentioned above, there are hundreds of variations on theHBBgene that can cause abnormal beta-globin formation, and a genotype describes the change in theHBBgene that a person inherits from their parents. In other words, the genotype describes the type of sickle cell.

The most common change inHBBgene leads to the SS genotype. Other types of sickle cells result from inheriting one gene for hemoglobin S and a different gene for abnormal beta globin. For example, inheriting one hemoglobin S gene and one hemoglobin C gene would result in an HbSC genotype. Some sickle cell genotypes are more common than others, and the severity of symptoms and complications vary among these different types.

A person with sickle cell trait inherits one copy of aabnormal (scythe)HBBgeneAbnormal (scythe)HBBgenea genetic mutation that produces hemoglobin S, which causes red blood cells to sickleand a copy of anormalHBBgeneHBBgeneGene that instructs cells to make a protein called β-globin (beta-globin). This means that although your red blood cells contain some HbA, a portion of your red blood cells (20% to 45%) consists of HbS. HbS levels in people with sickle cell trait are largely genetically determined. At rest, your red blood cells look healthy, smooth, and disk-shaped. However, under certain circumstances, your red blood cells may appearen forma de brings, and trait carriers may experience some of thesickle cell symptoms. Conditions such as high altitude, severe dehydration, and low oxygen can lead to complications including:

• Reduced blood supply to the spleen
• Muscle breakdown (rhabdomyolysis)
• Kidney damage and chronic kidney disease
• Bleeding (hyphema) and increased pressure in the eye (glaucoma) after eye injuries
• Sudden death with extreme exertion
• Kidney cancer (renal medullary carcinoma), extremely rare

Because a person with sickle cell trait may not have symptoms, they may not know they have it. However, they can still pass the monster (scythe)HBBgene along with their children. A simple blood test from your doctor can determine if you are a carrier and are at risk of passing on the abnormal gene.

sickle cell history