Presenting By

Ahmad Ali (42)

6th Semester

IBGE

Gene Therapy To Cure Thalassemia

Thalassemia is a genetically transmitted blood disorder characterized by absent or decreased

production of normal hemoglobin.

What is Thalassemia:

It leads to the death of about 50,000 to 100,000 people every year, whereas about 7% of the

world's population is a carrier of this hemoglobin disorder.

• Thalassemia, was first described in 1925 by a Dr Thomas Cooley while studing italian

childrens with severe anemia (low levels of red blood cells), poor growth, huge abdominal organs,

and early childhood death.

• In 1946, the cause of thalassemia was found to be an abnormal hemoglobin structure.

History:

• Thalassemia is caused by mutations in the genes that make hemoglobin.

• The mutations associated with thalassemia are passed from parents to

children.

• Now a days in Pakistan there is high prevalance of thalassemia mainly due

cousin marriages

Causes of Thalassemia:

•There are two primary types of Thalassemia disease:•Hemoglobin consist of two protein chain.1. Alpha chain 2. Beta chain So , type of thalassemia depends on

whether mutation is there in Alpha chain or Beta chain.

•Alpha Thalassemia • Beta Thalassemia

Types of Thalassemia:

Alpha thalassemia occurs when a gene or genes related to the

alpha globin protein are missing or changed

(Galanello & Cao, 2011).

Alpha Thalassemia:

Beta thalassemia occurs when a gene or genes related to the

beta globin protein are missing or changed(Galanello & Origa, 2010).

Beta Thalassemia:

•Blood transfusions• Iron chelation •Bone marrow transplant

•But all these treatment procedures have several complications.

e.g regular blood transfusion leads to iron over loaded in the body which in turn affect other body organs.

Treatments:

GENE THERAPY

A HOPE TO CURE THALASSEMIA

Gene therapy:• Gene therapy is a treatment that

involves altering the genes inside your body's cells.

• Gene therapy holds promise for treating a wide range of diseases

including thalassemia, SCA, hemophilia .

• Scientists pioneering a new gene transfer treatment for the blood disorder thalassemia, claiming they can

correct the lack of globin in patients' blood cells which causes the disease.

• The technology is based on delivery of a lentiviral

vector carrying the normal human globin gene into HSCs.

Lentiviral vectors belong to retroviridae family e.g Human immunodeficiency virus type 1, the

representative lentivirus.

Gene Therapy to treat Thalassemia:

• In 2007, a patient in France receive gene therapy for severe beta-Thalassemia

(Fucharoen & Winichagoon, 2012).

• Nine years after the procedure, he was still doing well without blood

transfusions means that he don’t need his monthly blood trasfusion.

Clinical Trials:

• Scientists took blood stem cells out of the patient, used a lentivirus to insert a working

hemoglobin gene, and put the stem cells back into the patient (Tsuruta, 2016).

Procedure:

Complications:

• There is only one patient in this study, but the technique needs to go through a lot

more testing before it is commonly used in hospitals.

• Also, scientists still don't know how to control where the virus inserts the working

hemoglobin gene.

References:Fucharoen, S., & Winichagoon, P. (2012). New updating into hemoglobinopathies. Int J Lab Hematol, 34(6), 559-565. doi:10.1111/j.1751-553X.2012.01446.x

Galanello, R., & Cao, A. (2011). Gene test review. Alpha-thalassemia. Genet Med, 13(2), 83-88. doi:10.1097/GIM.0b013e3181fcb468

Galanello, R., & Origa, R. (2010). Beta-thalassemia. Orphanet J Rare Dis, 5, 11. doi:10.1186/1750-1172-5-11

Tsuruta, T. ( 2016). Recent Advances in Hematopoietic Stem Cell Gene Therapy http://www.intechopen.com/books/innovations-in-stem-cell-transplantation/recent-advances-in-hematopoietic-stem-cell-gene therapy doi: 10.5772/53587