What kind of mutation is sickle cell anemia

A mutation in the HBB gene causes hemoglobin to clump together and change the shape of red blood cells. This can lead to anemia and blocked blood flow for people with SCD. This means it is a recessive trait.

It also means a person cannot get SCD later in life. HBB is the name of the gene that encodes, or gives instructions to, one of the protein pieces that make up hemoglobin.

Hemoglobin is made up of 4 globins, which each carry a molecule of oxygen. Beta globin is encoded by the HBB gene. Sickle hemoglobin, also called hemoglobin S HbS , is the most common form of abnormal hemoglobin.

It has 2 normal alpha globins but contains 2 sickle beta globins. Other forms of abnormal hemoglobin are caused by different mutations in the HBB gene. The mutation in beta-globin causes hemoglobin to cluster together and misshape the red blood cells. This leads to the symptoms and complications experienced by people with SCD.

Blood tests can identify HBB mutations and abnormal hemoglobin. We have 2 copies of 23 chromosomes, with 1 copy coming from each parent.

People with a single copy of the S variant and one copy of the healthy hemoglobin A variant have what is known as the sickle cell trait.

These individuals usually do not show any symptoms of sickle cell, but can still pass the S variant on to their biological children. Sickle cell disease can affect people of any ethnic background.

It is more common , however, in individuals of African, Mediterranean, Middle Eastern, and Indian ancestry. Sickle Cell Disease News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment.

This content is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

Envelope icon Subscribe to our newsletter Get regular updates to your inbox. People who carry only one copy of the sickle cell gene do not have the disease, but may pass the gene on to their children. The mutations that cause sickle cell anemia have been extensively studied and demonstrate how the effects of mutations can be traced from the DNA level up to the level of the whole organism.

Consider someone carrying only one copy of the gene. She does not have the disease, but the gene that she carries still affects her, her cells, and her proteins:.

Normal hemoglobin left and hemoglobin in sickled red blood cells right look different; the mutation in the DNA slightly changes the shape of the hemoglobin molecule, allowing it to clump together. This shape can sometimes interrupt blood flow.

There are negative effects at the whole organism level Under conditions such as high elevation and intense exercise, a carrier of the sickle cell allele may occasionally show symptoms such as pain and fatigue. There are positive effects at the whole organism level Carriers of the sickle cell allele are resistant to malaria, because the parasites that cause this disease are killed inside sickle-shaped blood cells.