Gene therapy Flashcards
What is gene therapy?
Treatment of a disease by the transfer of genetic
material into a patient’s cells.
What are chromosomal disorders?
Excess or loss of chromosomes e.g. down’s syndrome.
What are monogenic disorders (mendelian disorders)?
Inherited disorders caused by mutations in a single gene.
Autosomal dominant e.g. Huntington’s disease.
Autosomal recessive e.g. sickle cell anaemia, cystic fibrosis.
X-linked recessive e.g. haemophilia.
What are polygenic disorders?
Diseases associated with multiple genes (and environmental factors).
e.g. diabetes, cardiovascular disease, cancer.
What are the consequences of mutations?
Mutations within coding regions (exons) could lead to
generation of non-functional protein.
Mutations outside coding regions (introns) can cause
alternations in efficiency of transcription, translation, and splicing.
What are frame-shift mutations?
Addition or deletion of a single nucleotide that alters the reading frame.
Could occur due to strand slippage during DNA replication.
What is somatic gene therapy?
The ability to introduce genetic material (RNA) into an appropriate cell type or tissue in vivo in such a way that it alters the cell’s pattern of gene expression to produce a therapeutic effect.
Confined to the patient.
What is germ-line gene therapy?
When DNA is transferred into the cells that produce reproductive cells, eggs or sperm, in the body.
This type of therapy allows for the correction of disease-causing gene variants that are certain to be passed down from generation to generation.
Permanent transmissible modification.
Widely banned.
When is gene therapy appropriate?
Disease must be incurable by other means.
Molecular basis of the disease must be known.
Accessibility of target organ or tissue.
Longevity of targeted cells.
Low expression leading to large effect.
Ethical approval.
What are the obstacles to gene therapy?
Limited to somatic cells.
Specificity in targeting cells/tissues.
Duration of expression.
Side effects.
What is cell therapy?
Treatment of a disease by the transfer of cells into a patient.
What is in vivo delivery?
Genetic material is delivered to target affected cells (cancer cells or other) that remain inside a person’s body.
What is ex vivo delivery?
Mutated genes are delivered to a person’s body after the cells have been extracted and exposed to genome or gene editing.
What is somatic cell nuclear transfer?
The transfer of nucleus from adult cells to unfertilised enucleated oocyte or fusion of adult cell with an enucleated oocyte.
Oocyte reprograms the differentiated somatic cell.
What is a viral vector?
Viral vectors are tools commonly used by molecular biologists to deliver genetic material into cells.
This process can be performed inside a living organism or in cell culture.
