The following information may help to address your question:
What are genes?
Genes are instructions that tell our bodies how to grow, develop, and function. Every person has two copies of each gene, one inherited from each parent.
Last updated: 6/7/2016
What is gene therapy?
Gene therapy is an experimental technique that uses genes to treat or prevent disease. Gene therapy may allow doctors to treat a disorder by inserting a gene into a patient's
cells instead of using medications or surgery. There are several approaches to gene therapy currently being researched including:
- Replacing a gene with a mutation causing a disease with a normal copy of the gene
- Inactivating (knocking out) a copy of a gene with a mutation causing a disease
- Introducing a new gene into the body to help fight a disease
Gene therapy is a promising treatment option for a variety of diseases; however, it remains risky and is still under investigation to ensure it is used in a safe and effective manner.
[1]
More information about gene therapy is offered by GeneEd, a resource through the National Library of Medicine and the National Human
Genome Research Institute. To view, click
here.
Last updated: 6/7/2016
What is the genetic basis of erythropoietic protoporphyria?
Erythropoietic protoporphyria is caused by mutations in the
FECH gene.
[2]
Last updated: 6/7/2016
What is the normal function of the FECH gene?
The
FECH gene provides instructions for the production of an
enzyme called ferrochelatase. This enzyme is the eighth and the final enzyme involved in the production of heme. Heme is an essential part of iron-containing
proteins, including hemoglobin, which carries oxygen in the blood.
[3]
Last updated: 6/7/2016
How are changes in the FECH gene related to erythropoietic protoporphyria?
More than 110 different mutations (changes) in the
FECH gene have been identified in individuals with erythropoietic protoporphyria. These mutations may occur in one or both copies of the
FECH gene. A single
FECH gene mutation greatly reduces the activity of ferrochelatase, but typically does not cause symptoms. Symptoms of erythropoietic protoporphyria are caused by a build-up of porphyrins, chemicals in the body that assist in forming hemoglobin. Excess porphyrins can build up in the skin and other
tissues, causing a sensitivity to sunlight,
gallstones, and other symptoms related to erythropoietic protoporphyria.
[3]
Last updated: 6/7/2016
What is the status of gene therapy for erythropoietic protoporphyria?
At this time, gene therapy is not available for people with erythropoietic protoporphyria. Several gene therapy experiments have been carried out in mice with some promising results. We have located several full-text articles that discuss this topic. These articles are listed in
PubMed, a searchable database of medical literature.
Fontanellas A, Mendez M, Mazurier F, Cario-Andre M, Navarro S, Ged C, Taine L, Geronimi F, Richard E, Moreau-Gaudry F, Enriquez de Salamanca R, de Verneuil H;
Successful therapeutic effect in a mouse model of erythropoietic protoporphyria by partial genetic correction and fluorescence-based selection of hematopoietic cells. Gene Ther. 2001 Apr; 8(8): 618-26.
Richard E, Mendez M, Mazurier F, Morel C, Costet P, Xia P, Fontanellas A, Geronimi F, Cario-Andre M, Taine L, Ged C, Malik P, de Verneuil H, Moreau-Gaudry F;
Gene therapy of a mouse model of protoporphoria with a self-inactiving erythroid-specific lentiviral vector without preselection. Mol Ther. 2001 Oct; 4(4):331-8.
Robert-Richard H, Verneuil de C, Ged L, Taine V, Guyonnet-Dupérat M, Cario-André I, Lamrissi-Garcia Lalanne F, Moreau-Gaudry E.
Effective gene therapy of mice with congenital erythropoietic porphyria is facilitated by a survival advantage of corrected erythroid cells. Am J Hum Genet. 2008 Jan;82(1):113-24.
Last updated: 6/7/2016
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GARD Information Specialist
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