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	Presentations on Genetic Screening 3/19/03 Genetic Screening- An Introduction Kiera Introduction: Some genetic disease occur at a single gene, some of these are hereditary More will become evident as the human genome project continues Some mutations are always in the same position in all affected individuals = sickle cell anemia Some mutations occur in “hot-spots” in the gene, where mutations are more likely to be found Some mutations occur almost at random throughout the coding sequence Some mutations may occur in promoter sequence, exon deletions, or by gene or chromosomal translocation These mutations may or may not cause obvious differences. ex:premature amino-acid chain termination/truncated protein. These types of genetic mutations can be identified through genetic testing. Individuals that have an increased risk of diseases due to family history, medical signs/symptoms, may be screened for specific diseases. Screening may also take place when there are no specific risk factors.   Chromosome Analysis/Karyotyping: Karyotyping = an individual’s chromosomal composition During metaphase(during mitosis), the chromosomes condense and are easy to visualize. A staining process can be used to show the size and position of the centromere in each chromosome, which enables accurate identification of each chromosomes. Additional info can be obtained with different staining methods. Ex fluorescent probes DNA Sequence Analysis: In cases when a specific genetic mutation is known, as in the case of family history, DNA can be extracted, amplified, and sequenced. If the mutation leads to the loss or gain of a restriction enzyme site, the amplified product can be tested for the presence or absence of that site. This technique will say nothing about mutations in other parts of the gene or the whole genome. DNA Mutation Screening: Point mutations Amplified DNA is mixed and hybridized with a labeled single-strand DNA probe. The product is then run on a gel. DNA with a different mobility than that of a control DNA sequence can be detected and then be further analyzed by sequencing to determine the mutation. DNA Profiling: A genetic profile can be created for an individual by measuring the number and differentiation of microsatellites. Microsatellites are DNA sequences between two and several hundered nucleotides that show short, tandem repeats. When a large number of VNTR’s (variable number of tandem repeats) are compiled, they creeate a unique profile and can be used in the same way a fingerprint is used to identify an individual. Gene Discovery: Analyze DNA from both affected and nonaffected individuals. Can be used to show which genetic markers, or STR’s (short tandem repeats) best link to the disease. From this it is possible to create a linkage map and identify the gene location. Can Be Used For: carrier screening, which involves identifying unaffected individuals who carry one copy of a gene for a disease that requires two copies for the disease to be expressed prenatal diagnostic testing newborn screening presymptomatic testing for predicting adult-onset disorders such as Huntington's disease presymptomatic testing for estimating the risk of developing adult-onset cancers and Alzheimer's disease confirmational diagnosis of a symptomatic individual; and forensic/identity testing. Insurance Companies: Co are designed to calculate risk Health Insurance, Worker’s Compensation, or Life Insurance carriers Could use this information to deny services, or set premiums Helps to minimize their risk The idea behind Ins is to group people together collectively in order to protect the individual. Pioneers were groups of shareholders who shared profits and losses through inc or dec premiums Alternatively, the goal of most business practices is to maximize profits. The more information an ins co learns about it’s policy holders, the more accurately they would be able to tailor premiums so that they could exceed claims. The idea behind Ins is to group people together collectively in order to protect the individual. Pioneers were groups of shareholders who shared profits and losses through inc or dec premiums Alternatively, the goal of most business practices is to maximize profits. The more information an ins co learns about it’s policy holders, the more accurately they would be able to tailor premiums so that they could exceed claims. In the 1970’s, ins co began to become stock owned companies. This changes the motivation of the company from taking care of the individual, to maximizing profit. This leads to ins co learning the most about policy holders, and surcharging or denying individuals that pose a greater health risk. The book indicates that these practices lead to the unethical practice of creating different rates for African Americans and Caucasians. (Life Ins) Ins Co’s do not explain why the rates differ. Statistical correlation of health or mortality ignores the reason why the correlation exists or whether or not the correlation is deserved. Indeed the idea behind health care is to treat the patient without passing judgment on how they got that way. This creates a conflict if ins is seen as part of the health care system. Genetic consideration in setting premiums or offering coverage would reduce the risk of ins co. This could create a genetic underclass. This could also perpetuate the ins and healthcare crisis and create a system where only those that are healthy or those that could otherwise afford treatment would be offered coverage. This could lead to health coverage only for those that can afford it, perpetuating class divisions. No federal legislation has been passed relating to genetic discrimination in individual insurance coverage or to genetic discrimination in the workplace. Executive Order Protecting Federal Employees: February 8, 2000 Federal Employees: Prohibits federal employers from requiring or requesting genetic tests as a condition of being hired or receiving benefits. Employers cannot request or require employees to undergo genetic tests in order to evaluate an employee's ability to perform his or her job. Prohibits federal employers from using protected genetic information to classify employees in a manner that deprives them of advancement opportunities. Employers cannot deny employees promotions or overseas posts because of a genetic predisposition for certain illnesses. Provides strong privacy protections to any genetic information used for medical treatment and research. Under the EO, obtaining or disclosing genetic information about employees or potential employees is prohibited, except when it is necessary to provide medical treatment to employees, ensure workplace health and safety, or provide occupational and health researchers access to data. In every case where genetic information about employees is obtained, it will be subject to all Federal and state privacy protections. State Legislation: Existing state laws restrict the use of genetic info for ins purposes. No bans. AZ, MT, NJ, NM, VT, WI allow use as long is there is evidence to show that the results would change the number of claims. CA, MY, ME, NY forbid ins co to compel applicants to supply genetic info, but allow for its use   References:    ..
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