The temptation to test
When it comes to medical care, my husband and I generally call the shots in our family.
Most people would agree that this is an appropriate role for us to play, but certain medical decisions aren’t normally the purview of parents. Nor should they be. Foremost among them is the decision to screen children for some genetic diseases.
During the last 25 years, the number of genetic tests has increased rapidly. It’s now possible to identify alterations, or mutations, that increase the risk of a variety of diseases -- sickle cell anemia, cystic fibrosis, heart disease, diabetes and cancer to name a few.
Sometimes identifying a mutation early in life is beneficial. Newborn screenings for hypothyroidism and the metabolic disorder phenylketonuria, for example, can prevent potentially irreversible consequences that may develop if the conditions are left undiagnosed and untreated.
When genetic testing offers such obvious benefits to a child, the medical community generally agrees that parents should consent to it -- even seek it out. However, more often than not, the advantages of testing are not so clear-cut.
The ability to detect a genetic abnormality often precedes the development of the disease by many years. And, for many conditions, knowing that a child is genetically predisposed offers only anguish, not solutions -- no treatments can prevent the diseases or delay their onset.
Perhaps the most notable example of this is Huntington’s disease, an untreatable and debilitating neurological condition that causes uncontrollable body movements and damages intellectual functioning. Fifty percent of children with an affected parent will inherit the Huntington’s gene and go on to develop the disease. Although the gene is present from conception, symptoms of Huntington’s typically don’t occur until middle age.
With diseases that don’t manifest until later in life, most medical ethicists agree, parents should not make decisions about testing their child unless the results offer potential medical benefits. Instead, children should make these choices when they are mature enough to carefully weigh their options and understand the implications.
“Allowing parents to make the decision about testing for their children robs them of their ability to decide for themselves whether or not they want to know their genetic status,” says Dr. Mark Levine, chairman of the American Medical Assn.’s Council on Ethical and Judicial Affairs. In fact, studies have found that adults at risk for genetic diseases often decline testing.
Testing children could even be psychologically harmful, triggering feelings of fear and worry. “There’s no need to burden children with things that there’s nothing to do about,” Levine says. Parents too can be affected. Although a negative test result may produce a tremendous sense of relief, a positive test can elicit overwhelming anxiety and guilt.
Proponents of testing suggest that, on some level, many children are aware of their genetic risk of specific conditions, and that testing can help relieve their concerns. It might also provide the chance to gradually adjust to, and accept, their risk or, in some cases, diagnosis.
“The psychological impact of testing has not been well studied,” says Angela Bradbury, director of the family risk assessment program at Fox Chase Cancer Center in Philadelphia. She and other researchers are now beginning to explore such issues. “I think there is potential psychological risk,” she says. “But it depends on a number of factors -- the child, the parents, the family.”
I understand the temptation to test. But I would caution parents to examine what it really has to offer.
The results often aren’t as clear-cut as they’re perceived to be. In most cases, the presence or absence of a specific mutation doesn’t guarantee anything. Many girls who inherit one of the so-called breast cancer genes, for example, remain cancer-free, while others who don’t have the gene go on to develop the disease.
Simply put, “normal” results aren’t a guarantee of good health. Most diseases are acquired during one’s lifetime -- not inherited. In fact, only about 5% to 10% of cancers are inherited genetically; most are linked to behavioral and lifestyle issues such as smoking and alcohol.
Perhaps most important, parents must realize that detection doesn’t necessarily lead to a cure. Currently, our ability to treat genetic diseases lags well behind our ability to identify the genetic changes that cause them.
When children are young, it’s easy to worry about them and hard to imagine they’ll ever be prepared to make difficult choices (mine have a tough enough time making the easy ones). Although my husband and I may not agree with all the choices our children make, we do our best to keep quiet.
We allow our son to sleep in his clothes if he chooses, and we don’t bug our girls about getting their homework done even if they opt to put it off until the last minute. We’re pretty confident that, at some point, pajamas will begin to look more comfortable to our son, and the stress of leaving things until the last minute will reform our daughters. Even if this doesn’t happen, these decisions -- along with the bigger ones in life -- are ultimately theirs to make.
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Dr. Valerie Ulene is a board-certified specialist in preventive medicine practicing in Los Angeles. She can be reached at themd@att.net. The M.D. appears the first Monday of the month.
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Types of genetic tests
Predictive testing detects genetic abnormalities that increase a person’s risk of developing disorders later in life. Tests for the so-called breast cancer genes, BRCA1 and BRCA2, are good examples -- they identify women who have a very high chance of getting breast and ovarian cancer.
Presymptomatic testing determines whether a person will develop a genetic disorder before any signs or symptoms appear. It is typically performed in individuals known to be at high risk for a particular genetic disease such as Huntington’s.
Diagnostic testing helps confirm a diagnosis when a person is displaying signs or experiencing symptoms of a genetic disease. For example, children displaying significant developmental delays might be tested for Fragile X Syndrome.
Carrier testing determines whether an individual carries a genetic mutation that is linked to a particular disease. Although carriers remain disease-free, they can pass the gene on to their children. A child who inherits two genes -- one from each parent -- can develop the disease.
Prenatal testing helps identify genetic abnormalities before a baby is born.
-- Valerie Ulene
