Ethical implications and practical considerations of ethnically targeted screening for genetic disorders: the case of hemoglobinopathy screening

The prevalence of hemoglobinopathies differs among populations due to genetic differences and due to the protective effects of the heterozygote (carrier) state against malaria. Because of the difference in genetic distribution, public health programs have weighed the ethical versus practical implications of ethnically targeted versus universal newborn, and where applicable, prenatal screening. We examine newborn and prenatal screening for hemoglobinopathies in relation to the use of 'race' and ethnicity to assess risk for genetic conditions. First, categories of race/ethnicity are social constructs, therefore, observed or self-identified broad racial/ethnic categories are correlated but not necessarily reliable indicators of geographic ancestry or genetic risk. Second, targeting based on ethnicity poses serious issues of logistics and equity for public health programs and clinical services. In the past, newborn screening for hemoglobinopathies in the United States and United Kingdom was often selective, targeted to women of certain ethnic groups or areas with large concentrations of ethnic minority groups. Presently, newborn screening for hemoglobinopathies is universal in both countries and programs emphasize that individuals of all ethnic backgrounds are at risk for carrying a hemoglobin genetic variant. Reported race/ethnicity is still used as a criterion for offering prenatal carrier testing in the United States, where it is not a public health responsibility. In the United Kingdom, prenatal screening under the National Health Service is universal in high-prevalence areas and in low-prevalence areas is targeted based on reported ancestry. The continued use of targeted prenatal screening in both countries reflects the different purposes and modes of laboratory testing in newborn and prenatal screening. The ethical imperative to identify as many affected infants with life-threatening conditions as possible in newborn screening programs is not applicable to prenatal carrier testing. Because newborn screening dried blood spot specimens are tested for multiple disorders, targeted screening poses serious logistical challenges which is not the case in prenatal screening.