Transcript Beta Thalassemia

Beta Thalassemia
by 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
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
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
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.