Unformatted text preview: Reproductive Technology, Gene Therapy, and Genetic Counseling
Chapter 16 Fertility What does it mean to be fertile? Fecund What does it mean to be infertile? Who can be infertile? Preventing gamete Controlling Fertility transport Controlling egg production Physical and chemical barriers Fig. 16.1 Infertility Is Common Affects 5,000,000 couples in U.S. Both men and women 13% of all couples Most can be helped by assisted reproductive technologies Causes of Infertility Females: Problems with ovulation Oviduct problems Endometriosis Pituitary (hormonal) Males: Testis vein enlargement Unknown causes Duct obstruction Testicular failure From Table 16.1 Assisted Reproductive Technologies (ART)
Artificial insemination (AI): Males are infertile Sperm delivered to egg In vitro fertilization (IVF): Sperm and egg combined in a dish Assisted Reproductive Technologies (ART)
Gamete intrafallopian transfer (GIFT): Gametes placed in uterine tube Intracytoplasmic sperm injection (ICIS): Sperm injected into egg Fig. 16.2 Intracytoplasmic Sperm Injection Fig. 16.3 Ethical Issues: Risks 3X increase in ectopic pregnancies What is this? Multiple births: 35% twins or triplets Increased risk of low birth weight Ethical Issues: Risks Increased risk of transmitting genetic defects Potential increase risk of birth defects Ethical Issues: Selected Donor Siblings Prenatal diagnosis: select compatible stem cell donor Can currently be done Has been done Concern: reproductive technologies "could get out of control" Umbilical Cord Blood Umbilical cord blood = adult stem cells How are these different than embryonic stem cells? Benefits: your cells Downside: banking cord blood Most placentas are discarded Gene therapy = Gene Therapy 1990 Severe Combined Immunodeficiency SCID Ashanti DeSilva gene delivered by retrovirus Her immune system now works Ashanti is the only person to successfully receive gene therapy for SCID Gene Therapy Fig. 16.5 ~4,000 people received this therapy Setbacks in Gene Therapy Not completely safe: 1999 Jesse Gelsinger died treatment) 2000 two children died of leukemia (SCID immune response to the vector vector inserted itself into cell division gene Successful Gene Therapy
Gene therapy has treated: Cardiovascular disease HIV infection Most often used to treat cancer Ethical Issues
Currently Strict guidelines All patients are volunteers Informed consent Gene transfer is started after the case has been reviewed several times Types of Gene Therapy Somatic gene therapy = Germline therapy = Currently prohibited; alters all cells in the embryo Enhancement gene therapy = Genetic Counseling Provide information to families: Medical facts How heredity contributes to the disorder Risks to children Alternatives for dealing with risk Genetic Counseling Who should get genetic counseling? ...
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This note was uploaded on 04/04/2008 for the course BIOL 105C taught by Professor Drake during the Fall '07 term at Saginaw Valley.
- Fall '07