Newborn screening is used to detect disease in the newborn. Rarely do we consider that screening may uncover disease in the mother. Only in newborn screening for infectious diseases such as HIV is the identification of disease in the mother also considered a goal (1). Furthermore, it is also generally assumed that abnormal results are indicative of an underlying genetic disease and not dietary or iatrogenic factors. As this case nicely demonstrates, newborn screening can have implications and benefits not only for the baby but also for the mother. In addition, newborn screening can also benefit others when follow-up of positive test results includes further testing of asymptomatic family members, such as in medium chain acyl-CoA dehydrogenase deficiency (2).
This case also exemplifies an issue in newborn screening that needs to be considered. Many screening programs require a second dried blood spot sample to repeat the newborn screen when the first test is abnormal. If the second sample yields normal results, then the baby is deemed healthy and the first result is overruled as a false positive. By now, it should be well known that this approach is inappropriate for several fatty acid oxidation disorders, in particular very long-chain acyl-CoA dehydrogenase deficiency (3)(4). Had the same approach been applied to this case, the maternal condition would again have escaped detection because the results of follow-up acylcarnitine profiles in the baby were already normal.
With the expansion of newborn screening and the associated increase in complexity, the American College of Medical Genetics developed follow-up guidelines (freely available at www.ACMG.net) to help the practitioner efficiently and comprehensively follow up on abnormal newborn screening results. These practice guidelines are based on the analytes that can be abnormal in newborn screening and not just the conditions officially screened for in a particular screening program. These guidelines also include suggestions to evaluate family members when indicated.
Author Contributions: Each author confirmed they have contributed to the intellectual content of this paper and have met the following 3 requirements: (a) significant contributions to the conception and design, acquisition of data, or analysis and interpretation of data; (b) drafting or revising the article for intellectual content; and (c) final approval of the published article.
Authors’ Disclosures of Potential Conflicts of Interest: No authors declared any potential conflicts of interest.
Role of Sponsor: The funding organizations played no role in the design of study, choice of enrolled patients, review and interpretation of data, or preparation or approval of manuscript.
- © 2008 The American Association for Clinical Chemistry