Genetic Counseling and Testing
Many patients and their healthcare providers are unsure about what to expect
during a genetic counseling session. This outline is a general framework of what
patients can expect duringa genetic counseling appointment. Please keep in mind
every genetic counseling appointment is different, depending on the patient
family history, reason for referral, and patient concerns.
Genetic Counseling
Cancer Genetic Counseling
Preliminary Intake
Pedigree
Family History Risk Factors
Additional Risk Factors
Risk Assessment
Education and Communication
Informed Consent
Genetic Testing
Genetic Testing Flow Charte
GENETIC COUNSELING
Genetic counseling provides information and support to individuals and families who are concerned about, or may be at risk for, various genetic conditions. Genetic counseling consists of various subspecialties, including prenatal, pediatric, adult, and cancer genetics. In most subspecialties, the genetic counseling session includes: brief education of basic genetic principles, discussion of individual risks, information regarding relevant genetic conditions, risk assessment, medical management options, and a thorough discussion of options, including risk, benefits and limitations of these options.
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WHO PROVIDES GENETIC COUNSELING
Genetic counseling is often provided by genetic counselors, who are nationally certified, masters-level professionals trained specifically in medical genetics and counseling. However other health care professionals may also provide genetic counseling, including clinical geneticists, oncologists, specially trained nurses, etc. These individuals have various levels of education in genetics, and frequently counsel patients within the scope of their practice.
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CANCER GENETIC COUNSELING
The process of cancer risk assessment and counseling requires the integration of medical, scientific, family and environmental information. Healthcare professionals discuss a patient's specific risk factors and family situation. They provide education, risk assessment, and pre- and post-test genetic counseling (when appropriate) based on a patient's family history, medical factors, environmental factors, reproductive history and life-style choices. Patients learn about different risk factors for cancer, the inheritance of cancer risks, genetic testing, and management options. They are assisted in making informed decisions about methods for early detection, tests to detect increased risk, and prevention strategies. Patients may also meet with other members of a healthcare team, including medical, surgical, and/or gynecologic oncologists, nurse practitioners, or mental health professionals.
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PRELIMINARY INTAKE
Many centers have a genetic counseling program that requests specific information prior to the initial counseling visit. Other centers obtain personal and family history information during the counseling session. In most cases, the patient should expect to be asked some very specific questions about his or her own medical, hormonal, and family history. Genetic health professionals often ask about specific information in the family history. This information may include the current ages of family members (including aunts, uncles, cousins, and grandparents on both sides of the family), and the cause of death of any deceased family member. Information about cancer diagnoses is also important, including the age of diagnosis of any type of cancer in the family, as well as information about the specific type of cancer and/or treatment. It is often helpful for the patient to obtain copies of the medical records for some of the family members to clarify any missing information or incorrect information that has been passed through the family.
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PEDIGREE
Obtaining genetic information about relatives in a family is one of the most important factors in genetic risk assessment. A pedigree serves as a pictorial representation of a family, and allows genetic information to be presented in a straightforward, concise manner and is often taken at (or before) a genetic counseling session. An accurate, thorough pedigree is a permanent record of a family's genetic information, and provides information that assists in the risk assessment process. It is important to note that a pedigree is only as accurate as the information provided, which is why it is useful to ask patients to research specific family history information prior to drawing a pedigree. The utility of the pedigree may also be
limited by the skills of the healthcare professional constructing the pedigree, so it is also helpful to ensure the pedigree is drawn by someone with specific knowledge of genetics, and the particular condition(s) in the family history.
Click here to see an example of a pedigree.
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FAMILY HISTORY RISK FACTORS
There are several familial risk factors that may potentially impact a patient's cancer risk assessment, and many of them come to light when obtaining a detailed family history. In particular, there are several factors that are suggestive of a hereditary predisposition to cancer.
- Two or more close relatives with the same type of cancer.
- Patient and/or family member with multiple primary cancers.
- Patient and/or family member with bilateral cancers.
- Early age of cancer onset when compared with general population.
- Family history of a specific constellation of tumors that are associated with a known cancer predisposition syndrome.
ADDITIONAL RISK FACTORS
In addition to family history, other risk factors are also taken into account when performing a cancer risk assessment. Possible environmental exposures, lifestyle behaviors, and personal hormonal factors are all considered when assessing a patient's risk to develop cancer.
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RISK ASSESSMENT
Risk assessment often includes clinical criteria and various risk models that may be utilized to help interpret a patient's risk factors. Specific clinical criteria exist as guidelines to help assess risk for HNPCC using family or personal history factors. There are cancer risk models designed to assess a patient's individual risk to develop breast cancer such as the Gail and Claus models. Risk models also exist to help determine the chance that the patient carries a genetic abnormality in BRCA1/2 and HNPCC related genes, such as Shattuck-Eidens, Couch, and the Parmigiani model. Risk models are often used in conjunction with clinical judgment in deciding if genetic testing is appropriate for a particular patient, or to help quantify a cancer risk for a patient. For specific information about each of the risk models or criteria mentioned above, please refer to the links for HNPCC and breast cancer genetics.
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EDUCATION AND COMMUNICATION
In addition to obtaining the family medical history, the genetic counseling process also incorporates patient specific concerns, questions, risk tolerance and beliefs. The healthcare professional uses the information gathered during the session to perform a risk assessment and to engage the patient in a discussion regarding any misconceptions harbored by the patient regarding his or her risk. The healthcare professional is then able to integrate this information along with the patient's personal risk threshold. Understanding the psychological perspective of the patient allows the healthcare professional to choose an effective educational strategy to convey to the patient his or her actual cancer risk in a sensitive and effective manner. Individuals with a personal or family history suggestive of a known cancer predisposition syndrome are offered the option of pursuing genetic testing once the patient's risk tolerance has be reached and medical management options have been discussed.
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INFORMED CONSENT
Informed consent is the standard of care in genetic susceptibility testing since presently there is no known way to prevent cancer even if a cancer predisposition has been identified in an individual. There are several elements to the process of informed consent, including:
- A thorough discussion of the benefits of genetic testing, including the potential benefits of not pursuing genetic testing.
- A complete discussion of the risks of genetic testing, including the possible impact on family dynamics, lifestyle choices, and psychological well-being.
- A discussion of the implications of positive, negative or uninformative genetic test results. Genetic test results must be considered in the context of current clinical knowledge, personal/family history information, and statistical risk. A negative genetic test result does not mean that an individual is not at risk to develop cancer. Everyone has a risk to develop cancer regardless of any genetic testing result. An individual with a negative genetic test result may have an equivalent risk to the general population risk, or may still be considered to be at increased risk based on personal and family medical history, and thus should be managed accordingly.
- A discussion of the impact of genetic test results on unaffected family members. Although confidentiality is always a primary concern when discussing genetic testing, the potential ramification of a positive genetic test on other family members should be considered during the counseling session. Individuals should be encouraged to share genetic testing results with family members who could be directly impacted by the patient's genetic test results.
- Psychosocial support and guidance during the genetic testing process. Continual access and availability of a genetic counselor during this process and during medical management discussions can provide patients with assistance and reassurance.
- A conversation regarding the privacy of genetic test results. The New Jersey Genetic Privacy Act regulates the retention and disclosure of information obtained from genetic tests.
- A discussion of the potential implications of genetic testing on health and life insurance coverage. Although there is a paucity of documented reports of actual genetic discrimination, there is a fear of discrimination in the general population. A discussion regarding possible discrimination and other legal issues is important prior to genetic testing.
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GENETIC TESTING
DNA testing is available for several of the hereditary cancer syndromes. The current genetic testing for cancer predisposition may provide more individualized risk estimates for an individual but does not predict whether that particular patient will one day develop cancer, or the type of cancer that may develop. Ideally, genetic testing for a hereditary cancer syndrome begins with an individual who has already had a cancer diagnosis suggestive of a hereditary cancer syndrome. A negative genetic test in an affected individual is informative in that it means that the cancer diagnosis in that patient was not caused by the specific genetic alteration tested for (within, of course, the limitations of the genetic test itself). The cancer in the family may therefore be multifactorial, sporadic, caused by an undetectable genetic mutation, or caused by an unknown cancer-causing gene. However, a negative genetic test in an individual unaffected with cancer in the absence of a known mutataion in the family is completely uninformative. This result is uninformative because it is not known if there is a genetic mutation in the family that the patient did not inherit, or if the cancer in the family is being caused by some other (currently unknown) genetic abnormality, or some other factor (such as environmental) that may still render family members at increased risk.
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GENETIC TESTING FLOW CHART
Click here to see the flow chart in PDF format.
Note: Adobe Acrobat is required to open the PDF file. If you do not have the program installed, you can download it here.
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