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The human genome has come to your office. No longer limited to scientific inquiry, genomics has moved into patient care. So when patients ask questions about the possibility of developing a genetically linked disease or the cause of a child's condition, be prepared to respond, said four genetics experts at the Assembly.
The panelists -- Nancy Stevens, M.D., associate professor of family medicine at the University of Washington, Seattle; Louise Acheson, M.D., family medicine researcher at Case Western Reserve University, Cleveland; Joseph McInerney, M.A., M.S., of Lutherville, Md., director of the National Coalition for Health Professional Education in Genetics; and Susie Ball, M.S., genetic counselor and founder of the Central Washington Genetics Program at Yakima Valley Memorial Hospital -- reviewed case studies of patient concerns Oct. 14 during "Genomics: Answering Patients' Questions."
Patient questions generally follow the birth of a child with a congenital condition or the development of an illness in a relative. You should respond with solid understanding of the presenting condition, the family history and the community's resources, the panel advised.
Step one: Determine whether researchers have identified a genetic component to the condition in question, said Ball. Despite progress in the human genome, scientists have not identified genetic links to all conditions. Moreover, many conditions have either a genetic or an environmental cause.
"A congenital condition is not necessarily a genetic condition," she said. "Congenital only means the condition was present a birth."
Cystic fibrosis has a definite genetic link, but prelingual deafness could be inherited or could be caused by a prenatal complication, lack of oxygen during delivery or a postdelivery infection.
Step two: If the condition of concern to the patient is genetically linked, identify whether it develops from a dominant or recessive gene. Then develop a genetic map from family history. The patterns that emerge will help determine whether your patient inherited the suspect gene and will help identify the likelihood the illness will occur. The genetic map also will calculate the likelihood of passing the gene to offspring, said Ball.
Step three: Discuss genetic counseling. Most patients won't need genetic testing, which can cost thousands of dollars and has implications for health insurance, family dynamics and other issues, said Ball. She reminded the audience that a positive genetic test doesn't predict disease; for most illnesses, a positive test provides risk information.
"Genetics are not determinism," she said.
In addition, a test may reveal a patient's risk for developing an illness, but its value is limited if physicians have no option to prevent onset of the disorder.
For example, medicine has no guaranteed prevention for breast and ovarian cancer, said Acheson. Preventive mastectomy, oophorectomy and chemotherapy don't prevent all breast or ovarian cancers. Interventions for Alzheimer's disease have limited impact on illness progression. However, early intervention is highly successful and vital if prelingually deaf children are to grow into happy, productive adults.
Genetic counselors can help patients decide whether to proceed with genetic testing, said McInerney. See a related article (below) for online help identifying qualified genetic counselors.
Regardless of the decision on genetic testing, family doctors play an integral role in helping patients understand and respond to a genetically related condition, said Stevens. Family physicians should be prepared to educate patients about the illness or condition, the likelihood that children will inherit the illness, and the community resources that help patients and families cope with the condition.
To reach writer Leslie Champlin, e-mail lchampli@aafp.org.
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Copyright © 2004 by American Academy of Family Physicians.