Gene Therapy

Running Head Gene Therapy

Gene Therapy

Gene Therapy

Gene therapy is one of the promising fields of medicine which helps to treat and prevent incurable diseases . Some genetic diseases do not become manifest until well after birth , in some cases not until adulthood . In this case , gene therapy helps to identify and replace defective genes by healthy ones

Genes are specific sequences of nucleotides arranged along a DNA strand with start and stop signals , and written in a triplet-based code that scientists can read . Genes dictate the sequences of amino

acids that make up the proteins in our bodies . Genetic diseases (diseases caused by defective genes ) arise when these genes accumulate mutations , and an understanding of exactly what mutations are is important in understanding what gene therapy is intended to correct . Genetic mutations refer to any alteration in the inherited nucleic acid sequence of the genotype of an organism . Traditionally , geneticists defined mutations operationally i .e , only in terms of those genotypic changes resulting in some change in the resulting phenotype . However , as scientists developed the ability to measure changes directly in DNA itself , the definition of mutation has expanded to include any alteration in DNA , whether or not the alteration occurs in a gene , and whether or not the altered gene results in an altered phenotype (Walters Palmer , 1997

The transcription and translation processes involved in reading the genes that are a natural part of a cell 's own DNA are exactly the same processes used to "read " foreign genes introduced into a cell in the treatment known as gene therapy . The detailed knowledge gained over the past four decades about how these processes work in a living cell is the foundation upon which molecular medicine is built . Gene therapy is a technique for correcting defective genes responsible for disease development (Gene Therapy , 2005 . The fact that all living cells are diploid , i .e . have two copies of every gene , has important implications for genetic disease and for gene therapy . In almost all cases , a single good copy of a gene is sufficient to maintain biological function . That means that in for an animal to suffer from a genetic deficiency both copies of a given gene must be defective . That is the main reason that genetic diseases are relatively rare . But since one copy of a gene is usually sufficient for function , doctors do not have to repair nature 's mistake fully it is enough to replace or repair only one of the defective genes . Efficacy of gene therapy has been shown in viral diseases (such as HIV /AIDS , influenza , human papillomavirus infection various hepatitis strains , smallpox , and SARS , neurodegenerative diseases (such as Parkinson disease , amyotrophic lateral sclerosis , and Alzheimer disease , cancer , inflammatory diseases (such as rheumatoid arthritis , and autoimmune diseases (such as type 1 diabetes mellitus (Hood 2004 ,

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Gene therapy clinical trials were begun in 1990 . Over two hundred clinical trials for a number of additional genetic diss , as well as cancer and AIDS , have...