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Presented to: Dr Lesley Johnson Human disease=Beta Thalassemia By

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1 Presented to: Dr Lesley Johnson Human disease=Beta Thalassemia By

2 Diagnosis, Prevention, treatment, What causes which type? What is hemoglobin(structure)?Basic idea Treatment and prevention of Thalassemia in Pakistan Beta-Thalassemia major, intermedia, minor Summary Layout What thalassemia is? How the word was coined? Pattern of inheritance, Importance, Treatment and prevention & pioneering work in Pak. Diff. techniques, What can be done as biotechnologist? Ethical issues Facts and theories Types of Thalassemia Further classification Population affected

3 Inherited blood disorder, recessive trait name thalassemia =George Whipple and the William Bradford from the Greek thalassa for sea and -emia, meaning the blood. Types of Thalassemia Hemoglobin structure What is Thalassemia?

4 Types of Beta-thalassemia - Beta-thalassemia (Thalassemia major, Thalassemia intermedia, Thalassemia minor) - Beta-thalassemia with associated Hb anomalies (HbC, HbE, HbS/Beta- thalassemia (clinical - Hereditary persistence of fetal Hb and beta- thalassemia - Autosomal dominant forms - Beta-thalassemia associated with other manifestations

5 Hemoglobin Oxygen carrying tetrameric molecule consisting of two alpha and two beta subunit (α2β2),

6 Mutation in β globin gene leads to reduce or absent synthesis of Beta globin protein resulting in beta thalassemia results in microcytic hypochromic anemia (microcytic= small size RBCs, hypochromic= Light in color) Irregular peripheral blood smear which has nucleated RBCs Decreased amounts of hemoglobin A (HbA). Molecular Basis point mutations in the promoter, translational initiation codon, polyadenylation signal and an array of mutations leading to splicing abnormalities. What is Beta-thalassemia?

7 Cytogenetic location of HBB gene HBB gene is on the short arm of chrm# 11 (11p15.5), Gene causing beta thalassemia: Mutations in the HBB gene

8 Basic Idea Excess alpha globin left unbound clump inside of cell’s membrane Clumps kill the 95% cells itself Survived RBC’s lack hemoglobin do not last longer as normal RBC’s left untreated causes bone marrow for increase production of RBC’s vast majority dies increased production of RBC’s causes bone marrow grows up and bones to grow outward deformed body structure Damaged RBC’s overwhelm the spleen (increase in size) removal of spleen, lower some stress on body Without blood transfusion, patient will die prematurely

9 Beta-Thalassemia major/ Cooley’s anemia β0(zero) =complete absence of β- globin protein β+thalassemia= partial production of β-globin protein Must inherit the defective gene from both parents to develop thalassemia major Beta- thalassemia minor: Carries are actually known as having thalassemia minor. Patient may harbor a mild anemia but they a usually asymptomatic Β-thalassemia Intermedia : Occurs when both β- globin genes express decreased amount of protein or where 1 gene makes decreased amount and the other produced none.

10 predominant in Mediterranean countries, Central Asia, Middle East, India, Southern China, countries along the north coast of Africa. Highest rate is in Cyprus= 14%, Sardinia =10.3%, and Southeast Asia as well. carriers =80-90 million Epidemiology

11 Pattern Of inheritance

12 Diarrhea, enlargement of abdomen because of hepatosplenomagly and jaundice. If the patient left untreated heart failure, leg ulcers, extra medullary hematopoiesis and skeletal deformities. Skeletal changes are due to expansion of the bone marrow. Skeletal deformities include outgrowth of the skull, depression of the bridge of the nose and hypertrophy of the maxillae due to which upper teeth got expose Signs and symptoms

13 In Pakistan NIBGE national institute of biotechnology and genetic engineering has done pioneering work on thalassemia. Characterization of mutations by ARMS- PCR(amplification refractory mutation system) 50,000 registered cases of transfusion dependent about 5,000 Transfusion dependent children are born every year in Pakistan Ali Zaib Blood Transfusion Center, NIBGE, Fatmid Foundation Multan What’s the Importance in Pakistan? What is being done and what is needed?

14 No satisfactory treatment available for β- thalassemia Regular Blood Transfusion required to sustain life Iron Chelation Therapy (Annual cost US$4,400/patient, Annual average income in Pakistan US$420) Bone Marrow Transplant (Not affordable) Gene Therapy (Not affordable) THE ONLY AFFORDABLE SOLUTION IS Prevention through Carrier Screening Genetic Counseling Characterization of Mutations First Trimester Prenatal Diagnosis by CVS

15 Diagnosis Screening =mutations Monoplex ARMS-PCR (amplification refractory mutation system), Multiplex ARMS- PCR, radioactive and non-radioactive dot-blot or ASO (allele specific oligonucleotide) hybridization, DGGE (denaturing gradient gel electrophoresis), restriction endonuclease analysis Molecular genetics testing: Targeted mutation analysis, Sequence analysis, Deletion/duplication analysis Hematologic Diagnosis RBC indices, Peripheral blood smear, hemoglobin analysis:Qualitative and quantitative Hb analysis

16  Blood transfusions  Bone marrow transplantation  cord blood and bone marrow transplant is more successful)  chelation therapy to remove excess iron from the body.Transfusional iron overload is treated with Deferiprone, Deferasirox,Exjade( chelator administered orally.) Ferriprox.  World’s first successful treatment= 21 years old Frenchman for β thalassemia with GENE therapy in 2007 and was published in Nature.  Mediterranean Institute of Hematology has dealt with advanced cases of thalassemia successfully. Treatment

17 1. Genetic counseling 2. Avoiding cousin marriages having disease history 3. Pre-natal diagnosis 4. Carrier screening Prevention

18 What can be done as biotechnologist?  Replacement of hemapoietic cells that do not have the defective beta globin gene.  To replace defective beta globin gene in the bone marrow cells, this can avoid graft rejection.  Alternate form of treatment is presence of beta like chain i.e. Hb F (fetal hemoglobin). The genes are still present but they got inactive, if they can be reactive, patient with thalassemia can be cured.


20  After prenatal diagnosis, if the fetus is 100% expected to be diseased, termination of pregnancy is recommended, which as Muslim we believe is a murder. So issue arises here!!!!!!  THANKS  Questions Ethical issue

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