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Definition -Genetic testing. "the analysis of human DNA, RNA, chromosomes, proteins, and certain metabolites in order to detect heritable disease-related genotypes, mutations, phenotypes, or karyotypes for clinical purposes."

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Definition genetic testing l.jpg
Definition -Genetic testing

"the analysis of human DNA, RNA, chromosomes, proteins, and certain metabolites in order to detect heritable disease-related genotypes, mutations, phenotypes, or karyotypes for clinical purposes."

Holtzman NA, Watson MS, eds. Promoting safe and effective genetic testing in the United States: final report of the Task Force on Genetic Testing. Baltimore: Johns Hopkins University Press, 1999.

diagnosisof genetic disease in newborns, children, and adults

identificationof future health risks

prediction of drug responses

assessment of risks to future children


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QUESTION

Should genetic testing be required for jobs or parenthood?



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Background

  • Early writings occupational disease by Paracelsus, Agricola, Ramazzini in the 1500’s. Certain occupations increase the risk for certain diseases.

  • Ramazzini proposes that certain “morbid constitution”

  • J.B.S. Haldane in his book Heredity and Politics the “morbid constitution” could have genetic basis and suggest genetic testing.

    “The majority of potters do not die of bronchitis. It is quite possible that if we

    really understood the causation of this disease we should find out that only a

    fraction of potters are of a constitution which renders them liable to it. If so,

    we could eliminate potters’ bronchitis by regulating entrants into the potters’

    industry who are congenitally disposed to it.”

  • First genetics screening family history, gender, race and other phenotypic markers


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  • Haldene’s times denied employment by tar and creosote makers, fair-skin as a phenotypic marker, susceptibility to skin cancer in exposure to coal tar.

  • Acute hemolytic anemia among military personnel who received the antimalarial primaquine and were also heterozygous for glucose-6-phosphate dehydrogenase (G6PD) deficiency, in the 1960s

    G6PD deficient might also develop anemia under oxidant stresses from a variety of chemical exposures suchas aromatic nitro and amino compounds, metal hydrides, and dyes.

    In 1963, Herbert Stokinger and John Mountain were among the first to propose the use of genetic testing for G6PD deficiency to eliminate susceptible individuals from work with such chemicals

    • Most important, the determination affords, for the first time, an opportunity to make a susceptibility evaluation during the job placement examination, and, thus, avoids placing a worker in exposures to which he is inordinatelysusceptible.


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Cases

  • By 1973 other markers:

    • Alpha-1-antitrypsin deficiency,

    • Sickle cell trait,

    • Sensitivity to carbon disulfide and organic isocyanates

      Applications in the workplace …

      In 1978, DuPont testing of African Americans for sickle cell trait

      and restricting individuals from work with nitro and amino compounds

      Similarly, in the 1970s, the Air Force excluded African Americans with

      sickle cell trait from Academy admission and flight training because of presumed risk in hypoxic atmospheres

      At the same time, the Dow Chemical Company engaged in

      experimental studies of cytogenetic abnormalities, using them as

      genetic markers of acquired susceptibility for presumed future risk of

      cancer and reproductive problems among workers exposed to benzene

      and epichlorohydrin, although the information was not used

      in making employment decisions


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  • 1,147 Clinics

  • 612 Laboratories testing for

  • 1,352 Diseases

    • 1,063 Clinical

    • 289 Research only

      http://www.geneclinics.org/


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Types of Genetic Testing

classified according to their purpose

  • Genetic Screening

  • Carrier Testing

  • Prenatal Diagnostic Testing

  • Newborn Screening

  • Pre-symptomatic Testing

  • Susceptibility Testing

  • Diagnostic Testing

  • Forensic/Identity Testing


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  • Genetic Screening

    - to identify individuals who are at risk of developing a specific disorder. Screening is done so that further testing can be undertaken.

    • Ex. Women may be tested for BRCA1&2 - genes associated with breast cancer, so that preventative measures and early intervention can be considered.

  • Carrier Testing

    - to determine if an individual is a "carrier" of a gene for a recessive genetic disorder.

    Ex. couples undergo carrier testing for disorders such as Tay-Sachs disease, to assist in their reproductive decisions.

  • Prenatal Diagnostic Testing

    - to determine whether a fetus is affected by, or at risk for a genetic disorder before birth.

    Ex. Down's Syndrome


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  • Newborn Screening

    - focus on the identification of metabolic disorders in newborns. Early detection and treatment may be crucial to reduce the progression of such diseases.

    Ex. phenylketonuria (PKU). --Dietary intervention allows individuals with this condition to lead healthy and productive lives.

    • The most widely performed type in the United States today.

    • exist in all fifty states,

    • Most states mandate newborn screening and do not require parental consent.

  • Pre-symptomatic Testing

    - conducted on healthy individuals to determine whether or not they carry a genetic mutation that increases their likelihood of developing late-onset diseases and disorders.

    Ex. Huntington's disease and Alzheimer's disease.


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  • Susceptibility Testing

    - to identify individuals with genetic mutations that make them more susceptible to developing a disease when exposed to certain environmental elements.

    - often used to identify workers who may be susceptible to toxic substances that are found in their workplace which may cause disabilities.

  • Diagnostic Testing

    - to confirm a diagnosis already made by other methods.

    Ex. to confirm the diagnosis of certain forms of cystic fibrosis (CF).

  • Forensic/Identity Testing

    - to discover genetic linkages in criminal investigations between suspects and evidence or between children and their biological parents.

    http://www.biobasics.gc.ca/english/View.asp?x=780


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Reproductive genetic testing

  • Carrier testing

  • Preimplantation diagnosis is used following in vitro fertilization to diagnose a genetic disease or condition in a preimplantation embryo.

  • Prenatal diagnosis is used to diagnose a genetic disease or condition in a developing fetus. If the fetus is found to be affected with a disorder, the couple can plan for the birth of an affected child or opt for elective abortion.

  • Newborn screening


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The rapid advances made in genetic research and technology

Mapping of the human genome completed

on 2003.

Identify all the approximately 20,000-25,000 genes in human DNA,

  • Determine the sequences of the 3 billion chemical base pairs that make up human DNA,

  • Store this information in databases,

  • Improve tools for data analysis,

  • Transfer related technologies to the private sector, and

  • Address the ethical, legal, and social issues (ELSI) that may arise from the project.


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The rapid advances made in genetic research and technology

  • Genetic testing comes in two forms: screening and monitoring.

  • Genetic monitoring (generally supported by labor advocates) detects genetic abnormalities potentially caused by exposure to workplace toxins. It serves as an alert to hazards in the workplace, similar in principle to radiation detection badges.

  • Genetic screening , is used to detect either the potential for hereditary disease or susceptibility to workplace toxins. Genetic testing could in principle be used for pre-employment testing, employee placement, and risk avoidance -- all useful tools for employers.


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The rapid advances made in genetic research and technology

  • METHODS FOR GENE DISCOVERY

    • LINKAGE pedigree based

    • CANDIDATE GENE 1,000 – 2,000

    • GENOME WIDE ASSOCIATION




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Genome Wide Association

  • 500,000 Single nucleotide polymorphism (SNP)


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Extent of Genetic testing

  • 1982 when the former Congressional Office of Technology Assessment (OTA)

    N=550 company CEOs (65.2% response)

    19 companies (5%) had or was using genetic testing

    sickle cell trait, 5 for G6PD deficiency, 5 for alpha-1-antitrypsin deficiency, 2 for NADH hydrogenase deficiency, 3 for liver enzymes, and 5 for immune markers.

    Reason “Avoid lawsuits”

    Al Gore (then chair of house subcommittee):

    “potential to serve as a marvelous tool to protect the health of workers or a terrible vehicle for invidious discrimination”


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Extent of Genetic testing

  • The U.S. Congress' Office of Technology Assessment (OTA) reported that instances of screening jumped from 9,310 tests in 1991 to 63,000 tests in 1992

  • Around 1994 a study by Northwestern National Life Insurance Corporation of 400 firms found that “15% of the companies reported that by the year 2000 they planned to check the genetic status of prospective workers and their dependents before making employment offers”

  • By 1996, based on survey data from Geller et al. ,the Council for Responsible Genetics had identified over 200 cases of genetic discrimination

  • 1999 American Management Association 1054 companies (16.7% reported using genetic testing)

  • General guidelines for genetic testing were issued by the NIH Task Force on Genetic Testing in 1997


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PROs

  • Reduction in costs for employers, costs associated with occupational disease, loss of productivity, excess absenteeism, worker compensation premiums and legal liability.

  • It may not be economically feasible to ask the company to eliminate all the substances that put some individuals at risk.

  • Discriminatory? Employee selection is a screening, a individual does not have the right to work at a specific company or to hold a specific position (requirements of the job)

  • Helps both employees and employers by maintaining a healthy work place

  • Employers have a general ethical obligation of minimize the likelihood of illness or injury in the workplace.

  • Testing will provide workers with information at to what work environments to avoid


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PROs

  • Drastically reduce the allele frequency of carriers for a deleterious trait.

  • Reduce health insurance and society burdens.

  • Increase the unexpected portion positive variation.

  • Reduce absorptive mating

  • Identify potentially conflict personality traits in the parents


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Regulations

  • The Health Insurance Portability and Accountability Act of 1996 (HIPPA) prohibits

    • denial of coverage or assignment of higher premiums based on genetic information

    • the use of genetic test results on defining preexisting conditions in the absence of a corroborating medical diagnosis.

      There is no valid justification for employers to perform mandatory DNA testing on their employees.

  • The Americans with Disabilities Act (ADA) forbids using DNA testing information in employee evaluations.


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Regulations

  • Currently in the United States, no regulations are in place for evaluating the accuracy and reliability of genetic testing.

  • Most genetic tests developed by laboratories are categorized as services, which the Food and Drug Administration (FDA) does not regulate. Only a few states have established some regulatory guidelines.

  • The National Human Genome Research Institute (NHGRI) has a program, ethical, social, and legal implications (ELSI) research program


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Cons

Limited regulations

-Although legal protections for health and genetic information confidentiality exist on both the federal and state levels, they are often limited in scope and do not provide adequate safeguards.

www.health.state.ny.us/nysdoh/taskfce/screening.htm

Accuracy, reliability of the test

possibility for laboratory errors

-sample misidentification, contamination of the chemicals used for testing, or other factors


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Cons

Difficulties in interpreting a positive result

  • “The ability to identify particular genes precedesa thorough understanding of the implications of the presence of a defective gene and effective treatment. “(textbook by Maicna )

    • some people who carry a disease-associated mutation never develop the disease

    • How a test may guide clinical decisions? In some circumstances, predictive genetic testing may not provide medical preventive or treatment options.

    • The link between certain genetic traits, exposure to certain environments, and the likelihood of developingdisease many years into the future is not well understood.

      http://www.health.state.ny.us/nysdoh/taskfce/screening.htm


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Cons

Psychological burden

The psychological burden of being informed that one will develop a debilitating, fatal disease, such as Huntington's Disease, for which there is no cure, could be devastating.

Anxiety about false positive results =>Created fear and anxiety could affect a person’s performance

Parent-child relationship

harm that can be caused to the parent-child relationship by parental misperceptions about the meaning of a child's carrier status and the possibility that children will be subjected to needless, and potentially risky, medical interventions or monitoring.

http://www.health.state.ny.us/nysdoh/taskfce/screening.htm


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Cons

Unjust

  • While a person's skills, knowledge, or experience may be relevant in deciding whether a person is currently capable of performing a job, a person's genetic traits are not.http://www.health.state.ny.us/nysdoh/taskfce/screening.htm

    Health Care

  • “faced with the specter of an ever expanding pool of genetically defective "unemployables," dependent on the government for income and lacking access to health care” - “uninsurables”.

    • Persons who qualify for genetic testing may believe it is more difficult to obtain insurance because of the testing or are afraid to change jobs because of fear of losing health insurance. Allowing insurers' access to genetic informationprevents patients from getting needed help


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Cons

Employers have an obligation to provide a safe workplace, which should translate to removing the causes of occupational illness, rather than the victims.

Violation of an individual's right to privacy.

  • Employers have no right to require that an individual submit to genetic testing when that person shows no signs of a disease

  • Misuse of the information

  • The use of stored genetic information as an individual identifier.


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Cons

Quality of life

“Our culture does not reflect the ways in which people with disabilities experience and value our bodies and our lives,… I understand that it may be difficult for able-bodied people— particularly those in the health professions— to believe that disability may be experienced as different, not less.”

by DeRogatis, a nurse who speaks her own disability.

from textbook by Maicna p.251


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Cons

  • Society

    • the ability to eliminate potential offspring with genetic defects contributes to making society overall less tolerant of disability.

    • a decision to terminate a pregnancy is controversial.

    • a way of creating social categories.

      People with positive test results would be treated differently because of real or perceived genetic difference.

      Employee with genetic defects would be treated as “risk” groups

    • Since some genetic disease are associated with specific ethnic backgrounds (ex. Sickle cell anaemia in people of African decent), screening negatively impact on historically disadvantaged groups.

      Mcdonald & Williams-Jones, Journal of business ethics35: 235-241 2002


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What is Huntington's Disease (HD)?

  • causes uncontrolled movements, loss of intellectual faculties, and emotional disturbance.

  • a familial disease, passed from parent to child

  • each child of an HD parent has a 50-50 chance of inheriting the HD gene.

  • If a child does not inherit the HD gene, he or she will not develop the disease and cannot pass it to subsequent generations.

  • A person who inherits the HD gene will sooner or later develop the disease.

  • Whether one child inherits the gene has no bearing on whether others will or will not inherit the gene.

    (http://www.ninds.nih.gov/disorders/huntington/huntington.htm)


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Case study 1 (Textbook p.263 10.4 )

  • 39 years old man comes for presymptomatic DNA testing

    • asymptomatic

    • His father died with Huntington disease at age 50.

    • paying out-of-pocket to avoid his health insurance carrier

    • insists absolute confidentiality of test results

    • intends to tell no one, regardless of the outcome

    • His test is positive.

    • You happen to notice

      his occupation: pilot

      his employer :TransCoastal Airlines.

  • What do you intend to do under these circumstances?

  • Should he tell his employer?


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Case study2http://www.woodrow.org/teachers/esi/2002/Biology/Projects/p8/ethics.htm

Sue : an 19-year-old college student.

-responds to an ad in the local paper and volunteers to donate a blood sample to a company setting up a genetic database.

-on her follow-up visit, learns that she carries the gene for Huntington's Disease.

-realizes that one of her parents must also express the Huntington's gene and that they will most likely become symptomatic in the next ten years.

-notes that all of her grandparents, both maternal and paternal, have entered their 60s without symptoms.

-realizes that one of her grandparents may have had the gene, but never expressed the phenotypic disease.


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  • Should she tell her parents? Knowing that they are unable to have more children.

  • Assuming that she is relatively close to her parents, is there really any way she could (or would) keep this information from them? But do her parents have a right "not to know"?

  • Recently Sue and her boyfriend, Steve, have discussed marriage. Does her boyfriend have a right to know of her status before he makes plans to marry and have children? She knows that if she chooses to have children, there is a 50% chance that her child will inherit the disease.


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5 to have more children.. When Sue begins applying for jobs, does she have to enter this information into her medical history? What are potential repercussions if she does/does not offer this information?


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CASE: (Opinion) to have more children.

Lawsuit :

This is not genetic testing exactly, but illustrative

Hepatitis C infected individual sued Chevron Oil Company for denial of employment

Company argued hepatotoxic chemical exposure in the coke oven job exposed threat to his own heath.

The Supreme Court, in interpreting the ADA job qualification standard that “an individual shall not pose a direct threat to the health and safety of other individuals in the workplace,” allowed Chevron’s proposed extension of this to include the worker himself.

GENETIC TESTING IN THEWORKPLACE: Ethical,

Legal, and Social Implications Annu. Rev. Public Health 2004. 25:139–53


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GATTACA the job interview to have more children.