CLINICAL AND ETHICAL CONSIDERATIONS IN MANAGING CARRIER DETECTION

From the series Hidden Poverty in Illinois (2007) by photographer Kuni Takahashi. Kandee Neff, 19, reads a book on her bed on September 20, 2007, in the trailer where she lives with her father Lee, 63, and mother Sarah, 64, in Murdock, IL. Lee receives a disability check of $813 per month, and Sarah, who suffers from diabetes, earns $244 per month from her part-time job at Peace Meal but cannot afford the medication to control her diabetes. Printed with permission.

In their commentary, Miller et al. challenge the prevailing consensus that carrier information discovered incidentally in newborn screening should be disclosed.¹ The basis of their argument is that carrier identification reveals reproductive information, and disclosure takes away the child's right not to know this information and the child's right to privacy from other family members.¹ However, they discount the value of this information for the parents, because parents can obtain preconception or prenatal genetic testing and counseling themselves.¹

The challenge is quite timely given the rapid expansion of newborn screening in the United States following the development of a uniform panel by the American College of Medical Genetics and Human Resources Services Administration² and the endorsement of the panel by the Advisory Committee on Heritable Disorders in Newborns and Children.³ While we agree that newborn screening should not be done to provide reproductive information for parents, the arguments against disclosure by Miller et al. on the basis of a child's right not to know are weakened by their example: the identification of carriers of sickle-cell disease. Disclosure of the presence of the sickle-cell trait is warranted because carriers are at increased risk of heat stroke in extreme conditions.^4,5 A better example would be newborn screening for cystic fibrosis. There are no data to suggest that cystic fibrosis carriers have any additional health risks. As important, there are various screening methods of similar sensitivity and specificity to detect infants with cystic fibrosis. One method tests those with an elevated immunoreactive trypsinogen (IRT) for mutations in the cystic fibrosis trans membrane conductance (CFTR) gene (IRT/DNA). The other method collects a second sample and retests IRT (IRT/IRT). The first method detects cystic fibrosis carriers; the second does not. With either method, children with abnormal screens undergo sweat testing. Although IRT/DNA is more commonly used in newborn screening,⁶ we support IRT/IRT in public health screening programs to avoid carrier detection.⁷

In its 1994 report, Assessing Genetic Risks, the Institute of Medicine argued that the incidental identification of carrier status was a reason why newborn screening should require parental consent.⁸ We agree. In fact, we would go further and argue that the identification of healthy carriers and conditions in the uniform panel that do not fulfill traditional public health screening should be avoided, or pursued only within a research-based infrastructure that acknowledges these uncertainties and respects parental autonomy by engaging them in an informed consent process.^9,10