Gene Therapy and Genetic Counseling

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Gene Therapy and Genetic Counseling
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Treating Genetic Diseases

• Protein-based therapies

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Treating Genetic Diseases

• Somatic Gene Therapy
• Introducing functional genes into somatic cells
  to provide a nonheritable correction
• Note germ line therapy (altering gametes or
  fertilized eggs) is not being done for humans

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Target Sites for Gene Therapy
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Target Sites for Gene Therapy
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Target Sites for Gene Therapy
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Target Sites for Gene Therapy
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Applying Your Knowledge

• Liver
• Endothelium
• Muscle
• Lungs
• Skin

• Which tissue has cells lining an accessible
  passageway?
• Which tissue can regenerate?
• Which tissue has the advantage of producing blood
  vessels?

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Treating Genetic Diseases

• Gene delivery methods
• ---Vectors

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Methods of Introducing Genes

• ex vivo incorporate gene into cells outside the
  body and then deliver altered cells to patient
• in situ vector carrying the gene is injected
  into localized and accessible body part
• in vivo vector carrying the gene is introduced
  directly into the body, often through a blood
  vessel

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Initial Gene Therapy Treatments

• ADA deficiency
• periodic treatment of white blood cells in older
  children
• treatment of stem cells from umbilical cord blood
  in infants

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Initial Gene Therapy Treatments

• Ornithine Transcarbamylase (OTC) deficiency

Died from a massive immune response against viral
vector
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Current Gene Therapy Treatments

• Canavan Disease
• deficiency of aspartoacylase that leads to
  destruction of myelin-producing oligodendrocytes
• use of liposome or viral vector to introduce gene
  into brain tissue

Max Randell
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Applying Your Knowledge

• ex vivo gene therapy
• in situ gene therapy
• in vivo gene therapy

• Identify the type of gene therapy used in each
  case.
• For Andrew Gobea, ADA genes were introduced to
  his umbilical cord stem cells and these cells
  were delivered to his body.
• For Jesse Gelsinger, viruses containing the OTC
  gene were introduced into an artery leading to
  his liver.
• For Max Randell, viral particles with the
  aspartoacylase gene were injected into his brain
  at six sites.

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Suicide Gene Therapy For Treating Cancer
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Cancer Vaccine
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Genetic Counseling

• To help families understand and cope with genetic
  disease
• Provide information on
• Inheritance patterns
• Risk of inheriting a disease or recurrence
• Genetic tests and interpretation of results
• Available treatments for genetic disorders

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Genetic Counseling

• Approach is non-directive
• Timing
• Prenatal counseling
• Counseling of a family when inherited disorder
  has occurred