PHLB09H3 Chapter Notes - Chapter 9: Preimplantation Genetic Diagnosis, Newborn Screening, Genetic Testing
Genetic Choices- Chapter 9-pg. 634-645
• Genetic Testing- hekig for the hages i a perso’s DNA to hek for the possiility of geeti disorders
o Types of testing
o Newborn Screening- uncover genetic diseases for early treatment (first test was done for PKU which
was treated with a special diet)
o Carrier Testing- to determine whether or not someone is a carrier of a type of genetic disorder (2 copies
means the disease is present, 1 copy means that they are a carrier of the disease) ex. PKU and cystic
fibrosis
o Predictive Testing- to find out if someone is more likely to develop the disease later on in life
o Diagnostic Testing-to confirm or rule out a genetic disorder in someone with symptoms
o Prenatal Testing-to determine if a fetus have genetic abnormalities likely to physical or metal
impairments
o Preimplantation genetic diagnosis- to test embryos made through IVF for genetic abnormalities
• Genetic test almost never yields conclusive answers; only probabilities of developing the disease
• Example: BRCA gene which means that there is a higher chance of developing breast cancer
• Disease like Hutigto’s and Tay Sachs which develop due to a single gene mutation is easier to screen for
• But most disease form due to a change in mutations od several genes, interaction of multiple genes and
environmental factors
• Environmental influences later in life may cause mutations that the first initial test may have not been able to
screen for (all these genetic screenings do not guarantee and disease free future)
• The severity of the disease can also not be predicted; you may have the same genetic changes but the amount in
which it affects you cannot be controlled
• Some people may not want to find out if they have this disease because it may have no treatment
• Genetic testing can also take and emotional toll
o You a fid out that you do’t hae a disease that has affeted a lot of people i your faily ad oe
you fid out you do’t hae the disease you ay feel surior’s guilt
o if the new is bad you could feel depressed
o if the new is good you also may feel invulnerable
• being carriers may also make people feel like they have a genetic defect or that something is wrong with them; this
brings shame, guilt, and social stigma
• Each individual person has their own choice to find out whether or not you want to find out if you have the genetic
makeup for the disease
• A perso ith Hutigto’s has a 50% hae of iheritig the disease, if a perso kos that they might have this
disease does it mean that they have a moral obligation to be tested and they have to tell her children
o Do you have the moral obligation to know then the duty to warn if you have the disease?
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Document Summary
Example: brca gene which means that there is a higher chance of developing breast cancer: disease like hu(cid:374)ti(cid:374)gto(cid:374)"s and tay sachs which develop due to a single gene mutation is easier to screen for. But most disease form due to a change in mutations od several genes, interaction of multiple genes and environmental factors. Environmental influences later in life may cause mutations that the first initial test may have not been able to screen for (all these genetic screenings do not guarantee and disease free future) The severity of the disease can also not be predicted; you may have the same genetic changes but the amount in which it affects you cannot be controlled. Each individual person has their own choice to find out whether or not you want to find out if you have the genetic makeup for the disease.
