Genetic Testing of Asymptomatic Children
Deciding whether to test asymptomatic children is a very personal decision. No matter what choice a family makes, a person known to have multiple lesions would need to be tested first, as the “index patient.” Knowing the index patient’s exact mutation allows for specific testing of family members to determine if they are affected.
Once the family mutation is known, there are a number of reasons to test asymptomatic kids:
1. You will find out if your children don't have a mutation, which will let you stop worrying about their disease status. Each child of a parent with a mutation has only a 50% chance of inheriting the mutation.
2. If a child who does have a mutation has ambiguous symptoms, doctors and, particularly, insurance companies will be more driven to follow up with neurological testing. Children have died because they were not tested despite a known family mutation. They showed up in the ER and were sent home with diagnoses of migraine, or treated for flu instead of brain hemorrhage. Insurance companies have denied coverage for CT scans in undiagnosed children when the only symptom is headache. Less extreme, seizure disorders can be picked up sooner, before they cause developmental damage. ADHD can be understood in its context instead of being treated with stimulants.
3. You can take precautions for kids who have a mutation and you can eliminate the need to take precautions for kids who test negative. For example, it can be a burden to restrict ibuprofen but most doctors believe children with a mutation should stay away from this medication because of its blood-thinning properties. If parents don't know whether their child has the illness, they should be treating them as if they do, just in case. This means all children of a parent with multiple cavernous angiomas, regardless of their mutation status, should be restricted from taking ibuprofen if they haven’t had genetic testing. That’s an unnecessary restriction on kids who don’t have a mutation but don’t know it.
4. An MRI isn’t enough. A negative MRI in a child doesn’t mean the child doesn’t have a mutation. It simply means the child has no lesions at that moment, or very small lesions that are undetectable. In people with a hereditary form of the illness, more cavernous angiomas develop over time. A child, particularly those with a CCM1 or CCM2 mutation, may not develop their first lesion until later in childhood. Only a genetic test can determine if a child doesn’t have the illness or simply hasn’t developed a lesion yet.
5. You may want to consider changes to your will. Some parents choose to establish trusts for children with positive genetic results to protect the child’s ability to receive benefits should the child become disabled at some point in their life. This is something to discuss with an estate planning attorney.
However, there is also a negative side to testing asymptomatic children:
1. There is no denying that a positive genetic result changes childhood and family life. At minimum, it adds MRIs, visits to a neurologist, and anxiety to both the life of the child and the parents. It can mean seeking out a therapist, at least temporarily, to help with the emotional adjustment. There may also be issues between siblings if some test positive for a mutation while others do not.
2. You take away the child’s choice of knowing if they have a mutation. Doctors often advise parents to wait on testing for diseases that have no treatment. They suggest waiting until an individual reaches an age of consent so they can make their own choice about whether or not they want to know. One could debate whether cavernous angiomas truly fall in the "no available treatment" category, since there can be childhood onset; surgery intervention is sometimes critical; and, symptoms like seizure and headache do have treatments.
3. In the US, a positive genetic result can have a financial impact depending on your insurance coverage. The passage of the Affordable Care Act means your health insurance rates will no longer be affected, but adding an MRI and a specialist visit every year can be a strain because of co-insurance and co-pays. If testing itself isn't covered by insurance, then the cost of testing each child will be approximately $250. (This is the price to test a family member where the index patient’s mutation is known. Testing of the index patient can cost up to $5000).
4. In the US, children won't have difficulty obtaining medical insurance and they can't be discriminated against in employment as a result of a positive genetic test since the Genetic Information Nondiscrimination Act (GINA) was enacted. However, they may have difficulty buying life insurance if they start as adults. Children can be added to a parent's life insurance policy even with a positive genetic test. When they are adults, the children will be able to separate to their own policy and add more coverage as needed.
There are some conditions where testing should be strongly considered. If a parent’s testing finds a mutation on the CCM3 gene, testing of kids is necessary. At least 50% of people with a CCM3 mutation will have their first hemorrhage as children, lesions will bleed often, and such children will be at risk for a number of other disorders as part of what we're coming to understand is a CCM3 syndrome. Second, once we have drug treatments, it could be considered negligent to withhold something that could prevent a brain or spinal hemorrhage. Not all kids will get medication; just the ones who test positive for a mutation. So, in a few years, it’s likely all kids of parents with the hereditary form of the illness will be tested as part of the standard of care.
If you do decide to go ahead with genetic testing for your children, you’ll find information for you and your doctor in the Insurance/Lab Information for Doctor section.
---- Connie Lee, Psy.D., President, Angioma Alliance
Last update 2014.9.9