Chapter 064. The Practice of Genetics in Clinical Medicine (Part 6)

Follow-Up Care after Testing Depending on the nature of the genetic disorder, posttest interventions may include (1) cautious surveillance and appropriate health care screening, (2) specific medical interventions, (3) chemoprevention, (4) risk avoidance, and (5) referral to support services. For example, patients with known pathologic mutations in BRCA1 or BRCA2 are offered intensive screening as well as the option of prophylactic mastectomy and oophorectomy. In addition, such women may be eligible for preventive treatment with tamoxifen, or enrollment in a chemoprevention clinical trial. In contrast, those at known risk for Huntingtons disease are offered continued follow-up and supportive services,...
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Chapter 064. The Practice of Genetics in Clinical Medicine (Part 6) Chapter 064. The Practice of Genetics in Clinical Medicine (Part 6) Follow-Up Care after Testing Depending on the nature of the genetic disorder, posttest interventions mayinclude (1) cautious surveillance and appropriate health care screening, (2)specific medical interventions, (3) chemoprevention, (4) risk avoidance, and (5)referral to support services. For example, patients with known pathologicmutations in BRCA1 or BRCA2 are offered intensive screening as well as theoption of prophylactic mastectomy and oophorectomy. In addition, such womenmay be eligible for preventive treatment with tamoxifen, or enrollment in achemoprevention clinical trial. In contrast, those at known risk for Huntingtonsdisease are offered continued follow-up and supportive services, includingphysical and occupational therapy, and social services or support groups, asindicated. Specific interventions will change as translational research continues toenhance our understanding of these genetic diseases and as more is learned aboutthe functions of the gene products involved. Individuals who test negative for a mutation in a disease-associated geneidentified in an affected family member must be reminded that they may still be atrisk for the disease. This is of particular importance for common diseases such asdiabetes mellitus, cancer, and coronary artery disease. For example, a woman whofinds that she does not carry the disease-associated mutation in BRCA2 previouslydiscovered in her family must be reminded that she still requires the same breastcancer screening recommended for the general population.[newpage] Genetic Counseling and Education Genetic counseling should be distinguished from genetic testing andscreening, even though genetic counselors are often involved in issues related totesting. Genetic counseling refers to a communication process that deals withhuman problems associated with the occurrence or risk of a genetic disorder in afamily. Genetic risk assessment is complex and often involves elements ofuncertainty. Counseling therefore includes genetic education as well aspsychosocial counseling. Genetic counselors may be called upon by other healthcare professionals (or by individual patients and families) to address a broad rangeof issues directly and indirectly related to genetic disease (Table 64-1). The role ofthe genetic counselor includes the following: Gather and document a detailed family history; Educate patients about general genetic principles related to diseaserisk, both for themselves and for others in their family; Assess and enhance the patients ability to cope with the geneticinformation offered; Discuss how nongenetic factors may relate to the ultimate expressionof disease; Address medical management issues; Assist in determining the role of genetic testing for the individual andfamily; Ensure that the patient is aware of the indications, process, risks,benefits, and limitations of the various genetic testing options; Assist the patient, family, and referring physician in the interpretationof the test results; and Refer the patient and other at-risk family members for additionalmedical and support services, if necessary. Table 64-1 Indications for Genetic Counseling Advanced maternal (>35) or paternal (>50) age Consanguinity Previous history of a child with birth defects or a genetic disorder Personal or family history suggestive of a genetic disorder High-risk ethnic groups; known carriers of genetic alterations Documented genetic alteration in a family member Ultrasound or prenatal testing suggesting a genetic disorder The complexity of genetic counseling and the broad scope of geneticdiseases have led to the development of specialized, multidisciplinary clinicsdesigned to provide broad-based support and medical care for those at risk andtheir family members. Such specialty clinics are well established in the areas ofcancer and neurodegenerative disorders. The multidisciplinary teams are oftencomposed of medical geneticists, specialist physicians, genetic counselors, nurses,psychologists, social workers, and biomedical ethicists who work together toconsider difficult diagnostic, treatment, and testing decisions. Such a format alsoprovides primary care physicians with invaluable support and assistance as theyfollow and treat at-risk patients. The approach to genetic counseling has important ethical, social, andfinancial implications. Philosophies related to genetic couns ...