1. GENETIC SCREENING & GENE THERAPY Genetic screening & Gene therapy Dr. Dinesh T Junior resident, Department of Physiology, JIPMER Dr sclerodinesh

2. Introduction

4. History Technology to detect and treat inborn diseases - 1961. 1972 Friedmann and Roblin authored a paper in Science titled "Gene therapy for human genetic disease?“ The late 1980's, an international team of scientists began the project to map the human genome. September 14, 1990 - first approved gene therapy case in the United States took place.

5. 1992 - Doctor Claudio Bordignon, Milan, Italy performed the first procedure of gene therapy using hematopoietic stem cells. 1995 DNA testing in forensic cases gains fame in the O.J. Simpson trial. 2002 - first successful gene therapy treatment for adenosine deaminase-deficiency (SCID) 2003 – at University of California, Los Angeles research team inserted genes into the brain using liposome coated in a polymer called polyethylene glycol

6. 2006 - Preston Nix from the University of Pennsylvania School of Medicine reported on VRX496, a gene-based immunotherapy for the treatment of human immunodeficiency virus (HIV) that uses a lentiviral vector for delivery of an antisense gene against the HIV envelope 2007 – Moorfields Eye Hospital and University College London's Institute of Ophthalmology announced the world's first gene therapy trial for inherited retinal disease 2008 there were more than 1,200 clinically applicable genetic tests available.

7. Genetic screening

8. What is genetic screening? The newest and most sophisticated of the techniques used to test for genetic disorders. One of the fastest moving fields in medical science. A technique to determine the genotype or phenotype of an organism. Determines risk of having or passing on a genetic disorder.

9. Genetic screening Genetic screening is often used to detect faulty or abnormal genes in an organism Can detect some genes related to an increasedrisk of cancer Can detect some genes known to cause geneticdisorders

10. Genetic tests The analysis of chromosomes (DNA), proteins, and certain metabolites in order to detect heritable disease-related genotypes, mutations, phenotypes, or karyotype for clinical purposes.

11. Gene tests (also called DNA-based tests), in a broader sense Direct examination of the DNA molecule Biochemical tests for such gene products as enzymes and other proteins Microscopic examination of stained or fluorescent chromosomes

12. Genetic tests Who can order? What are the samples needed? How to interpret the tests? What are all the risks? Ethical considerations?

14. Prenatal diagnostic testing

15. Newborn screening

17. Pre implantation genetic diagnosis

18. Forensic/ identity testing

19. Research

21. Genetic screening Adult Polycystic Kidney Disease Alpha-1-antitrypsin deficiency Amyotrophic lateral sclerosis Alzheimer's disease Ataxia telangiectasia Central Core Disease Charcot-Marie-Tooth disease Congenital adrenal hyperplasia Cystic fibrosis Duchenne muscular dystrophy/Becker muscular dystrophy Dystonia Emanuel Syndrome Fanconianemia, group C Factor V-Leiden Fragile X syndrome Gaucher disease Hereditary Hemochromatosis Huntington's disease Hereditary nonpolyposis colon cancer Hemophilia A and B Inherited breast and ovarian cancer Marfan Syndrome Mucopolysaccharidosi Myotonic dystrophy Neurofibromatosis type 1 Phenylketonuria Polycystic Kidney Disease PraderWilli/Angelman syndromes Sickle cell disease Spinocerebellar ataxia, type Spinal muscular atrophy Tay-Sachs Disease Thalassemias Timothy Syndrome Galactosemia

22. Methods for prenatal screening

25. Family history of a single gene disorder

26. Family history of neural tube defect or other congenital abnormalities

27. Newborn Screening Tests: Maple Syrup Urine Disease Congenital Adrenal Hyperplasia Congenital Hypothyroidism Glactosemia Biotinidase Deficiency Homocystinuria Phylketonuria (PKU) Sickle cell and Other Hemoglobinopathies

28. Pre implantation Genetic Diagnosis (PGD) Pre implantation Genetic Diagnosis (PGD) uses in vitro fertilisation (IVF) to create embryos. Tests one or two cells from each embryo for a specific genetic abnormality. Identifies unaffected embryos for transfer to the uterus. The approach through PGD assists couples at risk of an inherited disorder to avoid the birth of an affected child without going through selective pregnancy termination.

30. To avoid having children with devastating diseases

31. Identify people at high risk

32. Provide doctors with a simple diagnostic test

33. Transforming it from a usually fatal condition to a treatable one

34. Possibility of laboratory errors

35. Potential for provoking anxiety, and risks for discrimination social stigmatization could outweigh the benefits of testing

36. Genetic counseling

41. Providing the options open to them in management and family planning in order to prevent, avoid or ameliorate it.

42. Autonomy of decision is crucial.

44. Gene therapy

45. Gene therapy is the replacement of faulty genes. Introduction of functional genetic material into target cells to replace or supplement defective genes, or to modify target cells so as to achieve therapeutic goals.

46. In theory it is possible to transform either somatic cells (most cells of the body) or cells of the germ line (such as sperm cells,ova, and their stem cell precursors).

49. Somatic Cell Therapy This is when a gene is introduced into a patient to help them recover from a disease.

50. Germ Line Therapy Changes are made to genes that will affect subsequent generations.

51. Applications of Gene Therapy Radical cure of single gene diseases e.g. cystic fibrosis, haemoglobinopathies. Amelioration of diseases with or without a genetic component e.g. malignancies, neurodegenerative diseases, infectious diseases.

52. Gene therapy concerns

53. Vectors in gene therapy: Non-viral methods Viruses Adeno-associated viruses Retroviruses Oligonucleotides Hybrid methods Lipoplexes and polyplexes Adenoviruses Naked DNA Envelope protein pseudotyping of viral vectors

55. Gene therapy using an adenovirus vector. A new gene is inserted into an adenovirus vector, which is used to introduce the modified DNA into a human cell. If the treatment is successful, the new gene will make a functional protein.

56. Non viral vectors Un complexed plasmid DNA DNA coated gold particles Liposomes DNA – protein conjugates

57. Modes of introducing genetic material

58. Un complexed Plasmid DNA Purified DNA or mRNA injected directly into tissues Injected into muscle and skin • Utility in immunization/ vaccination against Infectious diseases • Ectopic synthesis of therapeutic proteins as erythropoietin.

61. Skin tumours (melanomas)

63. DNA- Protein conjugates • Cell- specific DNA delivery systems • Utilize unique cell surface receptors on target cells • Chemical cross linking methods used

65. Gene Transfer techniques • In vivo Suspension containing vector is injected directly into the patient either systemically (i.v.) or directly into target tissue (e.g. malignant tumour) • Ex vivo Target cells (stem cells,myoblasts,fibroblasts etc) removed from the patient, treated with vector and injected back into the patient

69. Spectrum of gene expression Gene replacement for single gene disorders Gene repair Gene inactivation Ectopic synthesis of therapeutic proteins Cancer gene therapy

70. A) Immunodeficiency Disorders Adenosine Deaminase Deficiency X- linked SCID Chronic Granulomatous disease B) Liver Disease Familial Hypercholesterolemia Haemophilia A Target diseases

71. Hemoglobinopathies D) Lung Diseases • Cystic Fibrosis • α- 1 Antitrypsin Deficiency E) Skeletal Muscle • Duchene Muscular Dystrophy • Limb Girdle Muscular Dystrophy

73. Difficult to treat multi gene or multi factorial disease

74. Inserting gene into correct cells.

75. Controlling gene expression. Possibility of over expression

76. Damage to the host gene

77. Acquirement of virulence

79. Thank u all….