Chapter 8:Chapter 8:Genetic Genetic

EngineeringEngineering

by Mailee Phetby Mailee Phet

My Hoa NguyenMy Hoa Nguyen

What is gene therapy? It is possible that gene therapy given to an adult could reverse a genetic disease. If so, would that therapy also prevent any children the person had after gene therapy from inheriting the disease? Explain why or why not, and what factors the answer would depend on.

What is Gene Therapy?What is Gene Therapy?

The The Human Genome Project Human Genome Project may provide information may provide information that can be used to help replace genes that are defective that can be used to help replace genes that are defective or missing in people with genetic diseasesor missing in people with genetic diseases

experimental technique using genes to experimental technique using genes to prevent/ treat genetic diseasesprevent/ treat genetic diseases replace a mutated gene with a healthy onereplace a mutated gene with a healthy one deactivating a gene that isn’t functioning deactivating a gene that isn’t functioning

properlyproperly introduce a new gene in the body to help fight introduce a new gene in the body to help fight

the diseasethe disease

http://ghr.nlm.nih.gov/handbook/therapy/genetherapy

Germline Gene TherapyGermline Gene Therapy

normal version of gene is inserted normal version of gene is inserted into germ cellsinto germ cells those germ cells will divide normal those germ cells will divide normal

versions of the geneversions of the gene any zygote produced as a result of this any zygote produced as a result of this

germ cell will have a correct version of germ cell will have a correct version of the defective gene and will continue the defective gene and will continue passing it on to passing it on to theirtheir offspring offspring

http://kidshealth.org/parent/system/medical/gene_therapy.html

Somatic Cell Gene TherapySomatic Cell Gene Therapy

single defective cell taken out of an single defective cell taken out of an individual’s bodyindividual’s body

functional version of gene introduced functional version of gene introduced into cell in a laboratoryinto cell in a laboratory cells reproducecells reproduce copies of cells with a corrected version of copies of cells with a corrected version of

the gene is injected back into the patientthe gene is injected back into the patient the good gene ends with the patient the good gene ends with the patient

and is not inherited by their offspringand is not inherited by their offspring

In 1990, a 4 year old In 1990, a 4 year old girl named Ashi girl named Ashi DiSilva was the first DiSilva was the first patient to receive patient to receive gene therapy for gene therapy for SCID (severe SCID (severe combined combined immunodeficiency). immunodeficiency).

She became a She became a healthy adult with healthy adult with an immune system an immune system that was able to that was able to fight off most fight off most infections.infections.

However…However… gene therapy is still in its early stages and gene therapy is still in its early stages and

is far from perfectionis far from perfection it can only be used in diseases caused by a it can only be used in diseases caused by a

single gene malfunctionsingle gene malfunction• many diseases are caused by multiple genesmany diseases are caused by multiple genes

it can be hard to get a good gene to the it can be hard to get a good gene to the specific place it needs to bespecific place it needs to be• more damage can be caused by genes being more damage can be caused by genes being

put in the wrong placeput in the wrong place death can result due to infections and death can result due to infections and

invasions of other virusesinvasions of other viruses

http://www.wired.com/medtech/genetics/news/2007/08/gene_therapy

http://genome.gsc.riken.go.jp/hgmis/medicine/genetherapy.html

Ethical IssuesEthical Issues

Who decides what is normal and Who decides what is normal and what is a defect?what is a defect?

What kind of an impact will this have What kind of an impact will this have on people who are currently living on people who are currently living with these disabilities. Will this make with these disabilities. Will this make them feel worse about themselves? them feel worse about themselves?

Gene therapy is expensive so will Gene therapy is expensive so will only the rich have access to only the rich have access to treatment? What will happen to the treatment? What will happen to the poor?poor?http://genome.gsc.riken.go.jp/hgmis/medicine/genetherapy.html