Spotlight on Non-Invasive Prenatal Testing

Chris Kaposy suggests that Canada should learn from the United States’ failure to regulate the industry for Non-Invasive Prenatal Testing.

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Non-Invasive Prenatal Testing to detect genetic conditions in fetuses is a growing industry. Originally developed to screen traces of cell-free fetal DNA in the blood of pregnant women for the purpose of identifying fetuses with Down syndrome, Non-Invasive Prenatal Testing kits are now available for trisomies 13, and 18, sex chromosome aneuploidies, and a myriad of sub-chromosomal deletions that cause conditions such as Prader-Willi/Angelman syndrome, Wolf-Hirschhorn syndrome, and Jacobsen syndrome.

I recently co-authored an article in the journal Prenatal Diagnosis that details some of the impact of this expansion of prenatal testing on American groups that advocate for persons with the genetic conditions detected by this new form of prenatal testing. Advocacy group members, some of whom participated in writing the article, suggest that the development and the expansion of Non-Invasive Prenatal Testing have occurred without sufficient regulatory oversight in the United States, and without adequate genetic counselling resources.

The early industry-funded studies into Non-Invasive Prenatal Testing for Down syndrome related that these tests demonstrated a high degree of sensitivity (an ability to successfully identify fetuses with Down syndrome) and specificity (an ability to correctly identify fetuses without Down syndrome). Subsequent studies by independent researchers and clinics, however, were less definitive than the initial industry-based studies. These studies noted several problems including false positives, questions about positive predictive value, and other test limitations. Nonetheless, tests for rarer conditions such as genetic microdeletions were introduced to the American market with less supporting data than originally provided for Down syndrome testing.

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Furthermore, as the industry emerged, the United States Food and Drug Administration decided that Non-Invasive Prenatal Testing did not fall within its regulatory mandate. This type of testing was placed in the category of laboratory-developed tests that need not require review and approval. For these reasons – limitations of data, absence of data, and lack of regulatory oversight – the interpretation of Non-Invasive Prenatal Testing results can be challenging for anyone without training in genetic counselling.

Another problem with the increasing use of Non-Invasive Prenatal Testing is the misguided belief on the part of some women and couples that this is an effective diagnostic test (or nearly so), when it is really a screening tool. Distraught pregnant women who have received positive screen results often call or email patient-advocacy groups asking for help because they believe that test results are definitive. There have been reports of women who have terminated unaffected pregnancies on the basis of this screening test, having foregone follow-up testing with a reliable diagnostic test (such as an amniocentesis), because they believed that Non-Invasive Prenatal Testing results were diagnostic.

Because of uneven availability of genetic counselling resources in the United States, many women have turned to non-profit patient advocacy groups for assistance with Non-Invasive Prenatal Testing results. Groups such as the Trisomy 18 Foundation, 11q Research and Resource Group, and the Association for X and Y Chromosome Variations, field numerous email inquiries weekly helping expectant parents who have received Non-Invasive Prenatal Testing results. These groups are comprised of volunteers who often have family members living with the genetic condition in question.

Patient advocacy groups tend not to have expertise or training in genetic counselling, and they fundraise with activities such as bake sales. Meanwhile, the companies that develop and market Non-Invasive Prenatal Testing have enormous revenues. One company reported revenue of US$151 million in 2014. In contrast, the 11q Research and Resource Group reported revenue of US$58,756 in 2014.

Patient advocacy groups are pleased that expectant parents turn to them for help and that they are recognized as useful resources. These groups provide invaluable services and information. Nonetheless, pregnant women and their partners deserve better from the Non-Invasive Prenatal Testing industry, from professional groups, and from government. The responsible use of this technology requires better data, more transparency, greater regulation than what is provided in the United States, and greater support from the health care system.

As these tests continue to be introduced to the Canadian market, there should be appropriate regulatory oversight, adequate availability of genetic counselling from trained professionals, and a patient and provider education strategy about genetic conditions.

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Chris Kaposy is an Associate Professor of Bioethics in the Faculty of Medicine at Memorial University @ChrisKaposy