Principles of Genetic Counseling





Overview


Genetic counseling is a process of evaluating family history and medical information to advise patients of the risk of a genetic condition. This can have both a diagnostic and supportive element. The National Society of Genetic Counselors officially defines genetic counseling as, “the process of helping people understand and adapt to the medical, psychological and familial implications of genetic contributions to disease. This process integrates the following: 1) interpretation of family and medical histories to assess the chance of disease occurrence or recurrence; 2) education about inheritance, testing, management, prevention resources and research; and 3) counseling to promote informed choices and adaptation to the risk or condition.” Genetic counseling should include a discussion of available genetic screening and testing and informed consent with limitations, risks, and benefits associated with a genetic test. The patient should be made aware of the risk to develop disease and should be educated on the natural history of the condition and impact on the patient and at-risk family members, as well as potential interventions, research, and treatment.


Rapidly advancing genetic technology and decreased cost of genetic testing has led to increased patient demands and expectations. Although new genetic technologies afford increased information, the issues of genetic heterogeneity, such as variable penetrance and expressivity, variants of uncertain significance, and uncertain phenotype and unanticipated information, highlight the need and value of genetic counseling. The current climate of advanced prenatal genetic technologies to screen and diagnose genetic abnormalities in the fetus is also rapidly evolving. The complexity of genetic information available before birth has increased such that obstetric providers are challenged to have the time and expertise to discuss genetic testing options with patients. The obstetric provider should apply professional judgment to the specific clinical circumstance presented by the patient when determining whether the patient would benefit from consultation with a genetic specialist. Indications for genetic counseling in the obstetric patient include the following :




  • A known or suspected genetic diagnosis in the patient or family member



  • Suspected fetal anomaly



  • Abnormal or unanticipated result from a screening test



  • Abnormal or unanticipated result from a diagnostic test



  • Advanced parental age during pregnancy



  • Teratogenic exposure



  • Patient’s reported ethnicity associated with an increased prevalence of a genetic diagnosis



  • Recurrent pregnancy loss



  • Consanguinity



  • Any patient who wishes detailed information about carrier and/or aneuploidy testing beyond what the obstetric provider can deliver



Advances in genetic and genomic technologies offer new opportunities in prenatal testing and may empower families with knowledge about reproductive risk and support reproductive autonomy. These testing strategies, however, must be implemented in an ethically responsible manner and studied to determine best practice. Providing nondirective, comprehensive genetic counseling to obstetric patients is a critical component of this goal.




What Is the Role of a Genetic Counselor?


Genetic counselors are medical professionals with specialized graduate degrees in medical genetics, genomics, and counseling. In the clinical setting, a genetic counselor works to integrate genetic technologies into clinical practice, providing comprehensive genetic services to patients. Genetic counselors often are members of a healthcare team, but their training and expertise allow independent interaction with patients. The role of a genetic counselor includes the collection and evaluation of a medical and family history, providing guidance to the healthcare team on available genetic screening and testing, educating the patient about complex genetic principles, discussing benefits and limitations of genetic screening and testing in the process of informed consent, coordinating sample collection, promoting communication among medical professionals, interpreting and communicating genetic test results to the medical team and to the patient, advocating for patient needs as a result of a genetic diagnosis, and presenting risk-reduction strategies, management, or treatment options based on a genetic diagnosis. Providing these services, and others, allows the physician or allied health professional to be more efficient, enhance patient knowledge and satisfaction, as well as decrease liability and cost given their knowledge and role in the provision of care. Beyond direct clinical care, genetic counselors may work in a laboratory, have a role in genetic research, government, and legal affairs, or work for industry.


The American Board of Genetic Counseling (ABGC), through an examination process, certifies genetic counselors. In several states, a license is required to practice as a Certified Genetic Counselor (CGC) with the goal of ensuring competency. Licensure also allows genetic counselors to work in a more independent fashion. It also provides the credentials that many hospitals need to approve billing and reimbursement for these services and affords flexibility in the delivery of services.




What Are the Characteristics of a Patient Who May Benefit From Referral to a Provider With Genetics Expertise?


Referrals to a provider with genetics expertise should be considered if a patient is at risk for or affected with a genetic disorder. This may include a genetic counselor, medical geneticist, maternal fetal medicine specialist, or practitioner with specialized training in genetics. A provider with genetics expertise can obtain and critically evaluate the family history, identify the appropriate tests to order, provide pre- and posttest counseling related to genetic testing, and provide information about the treatment prognosis for patients or family members diagnosed with a genetic disorder. They may also recommend referrals to other medical specialists as indicated. Genetic counseling is also critical for helping patients understand implications of genetic test results and risk assessment for other family members.


Specific elements of a family history that should be considered for referral include one or more members with intellectual disability, structural birth defect, or the diagnosis of a genetic condition. Other family history elements that should prompt referral include one or more family members with sudden or early death of unknown origin and adult-onset health conditions such as cardiovascular disease or cancer, particularly if the cancer diagnosis was made in early adulthood. Patients who have experienced recurrent pregnancy loss, have a pregnancy at risk for or identified to have a health complication or birth defect, or are pregnant and are concerned about an exposure to medication should be offered a referral to a provider with genetics expertise. Other patients who may benefit from genetic counseling include patients in a consanguineous relationship or those patients who would like information and testing for genetic conditions that occur within their ethnic group.




What Are the Necessary Components of Pre- and Posttest Counseling to Consider When Counseling Patients on Carrier Screening?


Obstetric care providers are faced with many decisions when offering genetic screening and testing in an effort to meet the needs of their patient population and workflow. Pre- and posttest counseling are essential to the process of carrier testing in clinical practice. The global goals of pretest counseling are to provide education and personalized and nondirective information about testing options and facilitate informed consent. Many professional organizations have published components of pretest counseling that providers should be aware of when offering genetic testing ( Table 3.1 ). An obstetric care provider should identify those women with risk factors including advanced maternal age, family history of a genetic condition, or individual with features that may constitute a genetic diagnosis including intellectual disabilities, multiple miscarriages or birth defects, underlying maternal medical conditions (e.g., maternal phenylketonuria or cystic fibrosis), and/or teratogenic exposures that should prompt referral to a provider with genetics expertise. Any discussion of testing should include a review of the baseline risk to have a child born with a birth defect or intellectual disability, which is 3%–4% in the general population. Patients should also be informed at the beginning of the discussion that genetic testing is optional. Specific to carrier screening, using neutral and nonjudgmental language, the provider should broadly describe the types of conditions for which carrier screening is available and explain that some conditions may have poorly defined phenotypes. In addition, the provider should review the risks and benefits as well as the possibility for variants of unknown clinical significance. The concept of residual risk should be explained. A “negative” carrier screen result, for most conditions, only reduces the likelihood of the patient to be a carrier. There usually remains, however, a residual risk that may or may not be quantifiable based on the prevalence or mutation frequency of the condition. A plan for how and when results will be confidentially disclosed should be outlined. The patient should be informed that results of carrier screening are confidential. Providers are obligated to follow all Health Insurance Portability and Accountability Act (HIPAA) regulations. As cost may be an important factor in the decision-making process for an individual patient, the provider should be prepared to address this issue before testing, so a patient may obtain the necessary information.



TABLE 3.1

Components of Prenatal Pretest Counseling




























  • Genetic testing is optional




  • Assess risk for genetic disorders based on age, family history, maternal health, or exposures (medication, virus, etc.) to ensure appropriate test offered




  • Consider risks and benefits of screening versus diagnostic tests available to all women regardless of a risk status




  • Review clinical features of genetic conditions for which testing may be available




  • Describe performance of testing options, which may include sensitivity/specificity, positive/negative predictive value, concept of residual risk when applicable




  • Describe how chosen test is performed




  • Negative or low risk screening result does not guarantee a healthy child




  • Positive or high risk screening result does not mean fetus is affected




  • Discuss cost of testing




  • Review potential for unanticipated information, variant of uncertain significance, incidental finding if applicable




  • Discuss plan for disclosure of results

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Jan 5, 2020 | Posted by in PEDIATRICS | Comments Off on Principles of Genetic Counseling

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