Biology:Alpha thalassemia abnormal morphogenesis

Alpha Thalassemia-Abnormal Morphogensis is a group of blood disorders that affect the way the body makes hemoglobin. Hemoglobin is a protein found in red blood cells that carries oxygen throughout the body. It's made up of alpha globin and beta globin. Normally each person has four genes for alpha globin, Alpha thalassemia happens when one or more of the genes that control the making of alpha globin is absent or defective. It can cause anemia ranging from mild to severe. Also causing Genital abnormalities and terminal transverse limb defectiveness which is why it is called abnormal morphogenesis. This is most commonly found in people of African, Middle Eastern, Chinese, Southeast Asian and occasionally, Mediterranean descent.

Thalassemia

Thalassemia is an inherited condition. It's carried in the genes and passed on from parents to children. People who are carriers of a thalassemia gene show no thalassemia symptoms and might not even know they are carriers. If both parents are carriers, they can pass the disease to their kids. Thalassemia is not contagious.

While there are many different types of thalassemia, the two main are alpha and beta.

Beta Thalassemia

Beta thalassemia happens when the body has a problem producing beta globin, a component of hemoglobin. It is caused by mutations in the HBB gene which make instructions for making the protein beta globin.

Alpha Thalassemia

Alpha Thalassemia happens when the body has a problem producing alpha globin. This prevents oxygen from reaching the body's tissues and can cause a loss of red blood cells.

Some children with alpha thalassemia have no symptoms and require no treatment. Others with more severe cases need regular blood transfusions to treat anemia and other symptoms. They also may require surgery in early years to repair the abnormalities they were born with or else physical and occupational therapy to help live with terminal transverse limbs. The only way to get alpha thalassemia abnormal morphogenesis is by inheriting it from his or her parents from their genes. Humans are made up of trillions of cells that form the structure of our bodies and carry out specialized jobs like taking nutrients from food and turning them into energy. Red blood cells, which contain hemoglobin deliver oxygen to all parts of the body. All cells have a nucleus at their center which is kind of like a brain or command post of the cell. The nucleus directs the cell telling it to grow, mature, divide, or die. The nucleus contains DNA otherwise known as Deoxyribonucleic acid, a long spiral shaped molecule that stores the genes that determine hair color, eye color, whether or not the person is right or left handed, and many more traits. DNA, along with other genes and the information they contain, is passed down from parents to their children during reproduction. Each cell has many DNA molecules, but because cells are very small and DNA molecules are long, the DNA is packaged very tightly in each cell. These packages of DNA are called chromosomes, and each cell has 46 of them. Each package is arranged into 23 pairs with one of each pair coming from the mother and from the father. When a child has alpha thalassemia, there is a change in chromosome 16. Alpha globin is made on chromosome 16, so if any gene that tells chromosome 16 to produce alpha globin is missing or mutated, less hemoglobin is made. This affects hemoglobin and decreases the ability of red blood cells to transport oxygen to the body.

Hb Bart Syndrome and HbH

Alpha Thalassemia typically results from deletion involving the HBA1 and HBA2 genes. Both of these genes provide instructions for making proteins called Alpha goblin which is a component of hemoglobin. People have two copies of the HBA2 gene in each cell. Each copy is called an allele. For each gene, one allele is inherited from a person’s father, and the other is inherited from a person’s mother. As a result, there are four alleles that produce alpha globin. The different types of alpha thalassemia result from the loss of some sort or all of these alleles. Hb Bart syndrome, the most severe form of alpha thalassemia, results from the loss of all four alpha globin alleles. HbH disease is caused by loss of three of the four alpha globin alleles. In these two conditions, a shortage of alpha globin prevents cells from making normal hemoglobin. Instead, cells produce abnormal forms of hemoglobin called hemoglobin Bart (Hb Bart) or hemoglobin H (HbH). These abnormal hemoglobin molecules cannot effectively carry oxygen to the body’s tissues. The substitution of Hb Bart or HbH for normal hemoglobin causes anemia and the other serious health problems associated with Alpha Thalassemia abnormal morphogenesis. Two additional variants of alpha thalassemia abnormal morphogenesis are rated to a reduced amount of alpha globin. Because cells still produce some normal hemoglobin, these variants tend to cause few or no health problems. A loss of two of the four alpha-globin alleles results in alpha thalassemia trait. People with alpha thalassemia trait may have unusually small, pale red blood cells and mild anemia. A loss of one alpha-globin allele is found in alpha thalassemia silent carriers. These individuals typically live a life with no thalassemia related signs or symptoms.

Characteristics

Alpha thalassemia is a faintly common blood disorder worldwide. Thousands of infants with Hb Bart syndrome and HbH disease are born each year, particularly in Southeast Asia. Alpha thalassemia also occurs frequently in people from Mediterranean countries, North Africa, the Middle East, India, and Central Asia. People with alpha thalassemia abnormal morphogenesis encounter many different types of symptoms and characteristics of carrying and living with this trait. People with the characteristic features of alpha thalassemia experience a reduction in the amount of hemoglobin, that prevents enough oxygen to reach the body’s tissues. Affected individuals also have a shortage of red blood cells (Anemia) causing pale skin, weakness, fatigue, and more serious complications. There are two types of Alpha Thalassemia Abnormal Morphogenesis that can cause more major health problems. The more severe one is Hemoglobin Bart hydrops Fetalis syndrome or otherwise known as Hb Bart Syndrome. Another milder form is called Hbh Disease. HB Bart syndrome is characterized by hydrops fetalis, a condition in which excess fluid builds up in a body before birth. Additional signs and symptoms can include severe anemia, an enlarged liver and spleen (hepatosplenomegaly), heart defects and abnormalities of the urinary system or genitalia. As a result of these serious health problems, most babies with this condition are stillborn or die soon after birth. Hb Bart Syndrome can also cause serious complications for women during pregnancy, including dangerously high blood pressure with swelling (preeclampsia), premature delivery, and abnormal bleeding.

External links

• Genetics Home Reference
• KidsHealth.org
• www.ojrd.com