Genetic counseling is mostly recommended when you see multiple relatives in more than one generation who develop a condition, or if there's something profound that's occurring in the first few years of life, like a birth defect or mental retardation or children that are being born and then having a decline in their abilities.
So those individuals might want to come and see a genetic counselor to see if they are a carrier for an inherited disorder. People who are having children with a cousin, which is actually very common in many parts of the world, have a slightly higher risk to have a child with a group of genetic conditions that are inherited in what they call an autosomal recessive pattern.
Women who are over the age of 35 at the time of pregnancy have a higher risk to have a child with an extra chromosome. Down syndrome is the most common example of that, and so they might be offered screening tests, which might be a combination of blood tests performed on the mother and the amniotic fluid that surrounds the fetus, and possibly ultrasound to image the fetus to help look for those kinds of problems.
How should family histories be interpreted? If the health history indicates that they might be at higher risk for a condition, a genetic counselor or physician can help to sort out what kinds of interventions might be offered them, whether that's some kind of screening like mammography or colonoscopy, or a genetic blood test.
There are many different kinds of genetic blood tests. A careful medical family history helps a genetic counselor determine if certain genetic tests will be helpful in making medical screening choices or in making plans for having children.
A genetic test does not always predict a certainty of developing a medical condition. Some people will live to an old age without developing the condition. Therefore it is important to have genetic tests interpreted by health professionals with experience with inherited conditions. Also, just because a test exists doesn't necessarily mean that everyone should have it.
Do any issues of insurance discrimination ever arise? It's a very common concern of families. In fact, I think in some ways it's affecting people getting health care because they're so concerned about it. But there's very little evidence in the United States, or even in the world, that genetic tests are being used in a discriminatory manner.
But there are laws to protect patients from genetic discrimination. You can't have your insurance plans taken away from you if you have a genetic disease. That includes health insurance, life insurance, disability insurance and long-term care. What could potentially happen is when you apply for a new policy, they might not insure you or they might charge a higher rate.
Currently, there's a big Senate bill where they're hoping to really solidify those protections. Discrimination based on genetic diseases will be considered just like discrimination based on your sex or race or sexual orientation.
Do you think at times people overplay the role of genetics in disease? There's a lot of evidence that people overestimate their risk, so I think seeing a genetic counselor is often more reassuring than scary. For example, parents often think the risks of having a child with a genetic condition are much higher than the actual chances may be. And a person may be afraid of developing the same disease a parent or grandparent had, but, again, their chances are often not much different than the average person's. Genetic counselors can help put such risks into perspective.