Friday, March 23, 2007

Prenatal Gene Therapy

The timing of a genetic intervention (e.g. prenatal vs postnatal) will have an important impact on the efficacy of the intervention. The prospect of being able to administer a safe and effective prenatal therapy is appealing as many early onset genetic diseases begin to manifest early in life. This piece in Nature Medicine contains a useful table which lists the candidate diseases for prenatal gene therapy (diseases like CF). These candidate diseases are life-threatening disorders for which irreparable organ damage early in life is certain and for which no satisfactory treatment is available. And this Review in Gene Therapy (2005) highlights the complex scientific and ethical issues facing prenatal intervention.

This news piece in Medical News Today (also see this report) suggests that a prenatal intervention for CF may be possible in a decade. Here are a few excerpts:

A genetic scientist based at University College, London, Suzanne Buckley, has successfully used HIV as a genetical material carrier or "vector" to correct faulty cystic fybrosis genes in the cells of the lungs of mice.

Suzanne Buckley is presenting her findings on Wednesday 21st March at this week's British Society for Gene Therapy conference in Warwick. The title of her paper is "Significant lung transduction after in utero and neonatal 30 administration of lentiviral vectors".

,,,,Gene therapy introduces the hope that a person can be treated by removing the cause of the sticky mucous, by targetting the faulty CF genes in the lungs, rather than treating the result of the disease.

The idea is to remove faulty genes and insert the correct ones, so that future generations of the cell and the organism inherit the correct code and eliminate the disease.

Viruses are used in gene therapy as "vectors" to carry corrective genes to the target host cells. They are ideal because in their natural state they invade cells of living organisms, hijack their DNA and make it obey instructions that help the virus to replicate. Retroviruses like HIV go one step further, they insert a DNA copy of their RNA and merge it with the genetic material of the host cell.