Beta Thalassemiaby Sylvester Definition: Thalassemia is inherited disorders characterized reduced or absent amounts of hemoglobin, the oxygen-carrying protein inside the red blood cells.
Two Basic Groups of Thalassemia Disorder • Alpha Thalassemia • Beta Thalassemia: A person with this disorder has two mutated genes
There are 3 types of Beta Thalassemia • Thalassemia Minor • Thalassemia Intermediate. • Thalassemia Major or Cooley's Anemia
Thalassemias In the case of beta thalassemias, in contrast to alpha -thalassemias, the most frequently encountered molecular abnormalities are point mutations and short insertions or deletions limited to a few nucleotides chain synthesized chain is still synthesized. The quantity of globin chain, which is made, varies largely from one molecular defect to another, this chain may be structurally normal or abnormal · In beta 0 thalassemias , the gene is unable to encode for any functional mRNA and therefore there is no beta chain synthesize Two situations have clearly to be distinguished: · In beta + thalassemias, the mutated gene encodes for a small amount of normal mRNA and, thus, a low amount of
Beta Thalasemia • It is caused by a change in the gene for the beta globin component of hemoglobin • It can cause variable anemia that can range from moderate to severe. • Beta thalassemia trait is seen most commonly in people with the following ancestry: Mediterranean (including North African, and particularly Italian and Greek), Middle Eastern, Indian, African, Chinese, and Southeast Asian (including Vietnamese, Laotian, Thai, Singaporean, Filipino, Cambodian, Malaysian, Burmese, and Indonesian
Symptoms of Beta Thalassemia • It is characterize by severe anemia that can begin months after birth • Paleness • Delays in growth and development • Bone marrow expansion. • Untreated Beta Thalassemia major can lead to child death due to heart failure.
Alpha and Beta Thalassemias • The thalassemias are, therefore, considered quantitative hemoglobin diseases. • Because all types of thalassemia are caused by changes in either the alpha- or beta-globin gene. These changes cause little or no globin to be produced.
Treatment of Beta Thalassemia • Regular blood transfusion helps prevent severe anemia and allows for more normal growth and development • There are various medications that target the production of red blood cells (i.e. erythropoeitin)
References • First Known Heart Attack Associated With Beta- thalassemia Major Reported." Heart Disease Weekly February 22, 2004: 10. • Bowden, Vicky R., Susan B. Dickey, and Cindy Smith Greenberg. Children and Their Families: The continuum of care . Philadelphia: W.B. Saunders Company, 1998. • "Thalassemias." In Principles and Practice of Medical Genetics , Volume 2, edited by Alan E.H. Emery, MD, PhD, and David L. Rimoin, MD, PhD. New York: Churchill Livingstone, 1983. • Thompson, M.W., R. R. McInnus, and H. F. Willard. Thompson and Thompson Genetics in Medicine , Fifth Edition. Philadelphia: W.B. Saunders Company, 1991. • Olivieri, N. F. "The Beta Thalassemias." The New England Journal of Medicine 341 (1999): 99-109.