Marketing of expanded carrier screening
Chokoshvili D, Borry P, Vears DF. A systematic analysis of online marketing materials used by providers of expanded carrier screening [published online December 14, 2017]. Genet Med. doi:10.1038/gim.2017.222.
Prenatal carrier screening can be helpful to women and their families, but it is also a high-volume, lucrative business, with many commercial laboratories competing for the growing ECS market. Professional medical societies recommend making all screening candidates aware of the purpose, characteristics, and limitations of the tests, and of the potential significance of their results. As becoming familiar and comfortable with the tests and explaining them to each patient can be time-consuming, and daunting, many busy clinicians have started relying on marketing materials and other information from the commercial laboratories. Therefore analysis of the accuracy of such materials is in order.
Details of the study
Chokoshvili and colleagues performed a systematic analysis of the quality and accuracy of online marketing materials for ECS. They identified 18 providers: 16 commercial laboratories and 2 medical services providers. All described ECS as a useful tool for family planning, and some were very directive in stating that this testing is "one of the most important steps in preparing for parenthood." In their materials, most of the companies cover some limitations, such as residual risk, but none of the commercial laboratories indicate that ECS can overestimate risk (many variants have incomplete penetrance, meaning that some individuals with a positive test result may in fact be asymptomatic throughout their lifetime).
In addition, whereas a large amount of the marketing materials implies the test was developed in line with professional recommendations, none in fact complies with ACOG and ACMG guidance. Finally, though some of the online information provided by laboratories can be helpful, it is important for clinicians to remember that reproductive genetic counseling should be nondirective and balanced. Carrier testing should be based on patient (not provider) values regarding reproductive autonomy.
Ideally, carrier screening should be done prior to pregnancy
Determining that a woman carries a genetic disorder in the preconception period allows more time to evaluate her reproductive partner. If both partners in the couple carry the same genetic disorder, there are more options available to avoid an affected pregnancy. These options include the use of an ovum or sperm donor, or use of preimplantation genetic diagnosis on embryos conceived through in vitro fertilization. While obstetric providers commonly offer carrier screening, and most women are only screened during pregnancy, such genetic testing should be part of pregnancy planning. When gyn providers see patients who are considering a pregnancy, he or she should discuss the options of expanded carrier screening, or ethnicity-based screening.
Summary
ECS increasingly is being adopted into clinical practice. According to ACOG, traditional ethnicity-based screening, panethnic screening (the same limited panel of tests for all patients), and ECS are all acceptable alternatives for prenatal carrier screening.3 For providers who offer ECS, it is important to have a good understanding of each selected test and its limitations. Providers should have a plan for following up patients who have positive test results; this plan may include having genetic counseling and prenatal genetic diagnostic testing in place. Although treatment is available for a few genetic conditions, for the large majority, prenatal screening has not been proved to lead to improved therapeutic options. Providers should try to make sure that patients do not have unrealistic expectations of the outcomes of carrier screening.
WHAT THIS EVIDENCE MEANS FOR PRACTICE
Laboratories' educational materials can be useful, but clinicians must carefully assess them before recommending them to patients. Some commercial laboratory information is helpful and balanced; other information is directive or even coercive. Nonbiased information on prenatal genetic testing, for both patients and clinicians, is available in the Genetic Education Modules offered by the Perinatal Quality Foundation (https://www.perinatalquality.org).
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