From Autism to Breast Cancer to Prenatal Genetic Testing, Genetic Counselors Can Help
With the influx of genetic tests now available for a wide variety of conditions and diseases, people are overwhelmed. Part of our job as genetic counselors is to stay on top of the latest advancements in genetic testing to provide the best possible options and counsel for our patients. This week, I’m joining more than 2,000 of my genetic counselor colleagues in New Orleans to do just that – come together for NSGC’s Annual Education Conference to learn about new research and best practices.
Research presented at the conference explores new findings in the areas of autism, breast cancer and prenatal diagnosis. These studies reveal that genetic testing doesn’t provide all of the answers, and shows that genetic counselors can play an important role in guiding patients through the genetic testing process.
Here are some highlights from the meeting:
Genetic Testing Doesn’t Always Shed Light on Cause of Autism
Desperate to find out why their child has autism, parents may turn to genetic testing only to find out that these tests often don’t provide the answer. A new University of Colorado Denver Anschultz Medical Campus study found an inherited cause of autism spectrum disorder in only 17 percent of the 107 children tested.
Each patient in the study had an average of three genetic tests ordered, and chromosomal microarray analysis, a technique that looks for extra or missing chromosomal segments, provided the highest number of diagnoses.
Because genetic testing for autism can be limited and complex, if a genetic cause is found through testing, a genetic counselor can explain what the findings mean along with the chances that future children would develop autism.
Genetic Testing Not Necessary for All with History of Breast, Ovarian Cancer
In this study, nearly a third of patients who had breast or ovarian cancer or a family history of the disease ultimately did not undergo genetic testing for BRCA1 or BRCA 2 mutations. The University of Michigan study of 10,726 patients, who saw a genetic counselor, identified the most common reasons for not undergoing testing. These include:
- Not being the best test candidate (27 percent),
- Testing was not clinically indicated (22 percent),
- Testing was declined for personal reasons (17 percent), and
- Insurance coverage was inadequate (13 percent).
A patient who does not have cancer, but has a strong family history – such as a mother or sister with cancer – is not considered a good candidate for testing. In those cases, the family member who has cancer should be tested first. If a genetic mutation is found, the family member who does not have cancer should then be tested for that mutation.
Part of our job as genetic counselors is to stay on top of the latest advancements in genetic testing to provide the best possible options and counsel for our patients.
Also, testing is not indicated in cases where it is unlikely the cancer was caused by a genetic mutation. For example, if an older woman with breast cancer had relatives who also got the disease at an older age, it is unlikely the cancer is inherited because one in eight women eventually get breast cancer. In some cases, testing would be recommended, but sometimes insurance coverage excludes genetic testing or requires a high co-pay, presenting a barrier for some patients.
In instances where genetic testing is not indicated, a genetic counseling appointment can help guide and reassure patients and their doctor about the appropriate cancer screening and surveillance options.
Increasingly Ordered, NIPT Testing Isn’t for Everyone
Obstetricians are ordering or offering non-invasive prenatal testing (NIPT) more routinely, even for women not at an elevated risk of having a child with a chromosomal problem such as Down syndrome. NIPT is a simple blood test that can be performed early in the pregnancy (as early as 10 weeks), is up to 99 percent accurate in detecting Down syndrome and other chromosomal abnormalities and is less risky than other methods. But a new University of Texas survey suggests not everyone wants or should get the test and that meeting with a genetic counselor should be recommended prior to testing. The survey of 149 women who had genetic counseling and were offered NIPT along with invasive options found:
- 17.5 percent of women declined the NIPT test, even though the test poses no risk to the fetus (as other definitive testing methods – amniocentesis and chorionic villus (CVS) sampling - do).
- Many women don’t realize they have had an NIPT test. In an analysis of 16 women who had NIPT prior to the counseling appointment, 63 percent didn’t realize they’d had the test.
Prenatal testing is moving faster than people can keep up with. Most often, women choose NIPT do so because they want to learn more about their pregnancy; however, having that information may make some women anxious. As a genetic counselor specializing in prenatal genetic testing, I encourage women to be proactive and have a voice in which prenatal screening tests are performed during their pregnancy and express their desires to their obstetricians.
Genetic counselors are available to explain the countless options and help patients make informed decisions.
Jennifer Hoskovec, MS, CGC, is president of the National Society of Genetic Counselors, and the Director of Prenatal Genetic Counseling Services at the UTHealth Medical School in Houston.