The Future of Newborn Screening
Not all individuals are born healthy, and some babies require treatment as soon as they enter the world. Though newborns may show general indicators, like a failure to thrive or meet milestones, it is not always easy to identify the specific treatments they require. This is often the case with inborn errors of metabolism, mutations in key enzymes or pathways that alter an individual’s ability to synthesize or breakdown macromolecules.1 One tool that can be employed to identify these diseases is newborn screens, which can be utilized to specifically identify lysosomal storage diseases. These screens permit the early identification of diseases, allowing for rapid treatment that can be crucial for newborns to not only survive but thrive. Ultimately, newborn screening is an incredibly useful tool in identifying metabolic diseases such as lysosomal diseases, and current research strives to improve these tests.
Lysosomal storage disorders represent a subcategory of inborn errors of metabolism. This subgroup encompasses over 40 disorders, including Gaucher disease, Pompe disease, and MPS I, making it one of the largest groups of genetic disorders.1 These diseases arise from mutations and alterations associated with the lysosome, a cellular enzyme responsible for the breakdown of certain toxic substances in the body.2 Specific symptomatology varies between different disorders, but all lysosomal storage disorders result in the accumulation of molecules that would normally be broken down by healthy, functioning lysosomes.2 This accumulation may have toxic effects on the body, including damage to the nervous system, heart tissue, or skeletal muscle.3,4 Therapeutic options such as bone marrow transplants exist for individuals with these conditions, but it is often recommended that these therapeutic strategies be implemented prior to the onset of symptoms.1 It is therefore critically important to identify lysosomal storage disorders quickly and accurately as soon after birth as possible.
Newborn screening is an effective method used to identify lysosomal storage disorders at a young age. Screenings involve taking a blood sample from newborns. Samples are then analyzed via tandem mass spectrometry to determine concentration and activity of certain compounds.5 This provides information about which compounds may either be absent or accumulating in excess in the body, altering practitioners to potential abnormalities in lysosome function.6 Newborn screening is incredibly important to allow for the rapid development of treatment plans; however, due in part to the fact that testing is done prior to the emergence of symptoms, results are not always accurate. Tests can generate both false positives and false negatives.7 There are risks associated with both of these outcomes, as false negatives prevent practitioners from identifying abnormalities and developing treatment plans, while false positives may cause patients and families to experience undue stress. Thus, it is crucial to improve tests such that families are accurately informed about their newborn’s health.
A variety of current research aims at improving the accuracy of newborn screening. Recent research conducted in the United States specifically aims to reduce false positive results in an attempt to minimize the trauma that may be experienced by families.7 This study implemented the use of software that analyzes results from a newborn’s blood samples in order to generate a particular “score.” The score is compared to a database of known patient profiles in order to determine the likelihood that a newborn has the same disease as the patients.7 By comparing results to existing patients, this system work aims to limit false positive results and increase the precision in newborn screening for lysosomal storage disorders.
Ultimately, lysosomal storage disorders represent a massive group of disorders that have varied and devastating effects on individuals. Multiple treatment options are available, but they often require early diagnosis. Newborn screening programs are an excellent way of ensuring early diagnosis and allowing for the best treatment possible to be delivered, but tests and data interpretation must be improved to limit the risk of false positives. Current research is taking steps to do this, but more exploration is still needed to optimize newborn screening programs so that they can continue to have an invaluable impact on the lives of newborns and their families.
1. Meikle PJ, Hopwood JJ. Lysosomal storage disorders: emerging therapeutic options require early diagnosis. Eur J Pediatr. 2003;162(1):S34-S37. doi:10.1007/s00431-003-1348-y.
2. Vellodi A. Lysosomal storage disorders. Br J Haematol. 2005;128(4):413-431. doi:10.1111/j.1365-2141.2004.05293.x.
3. National Organization for Rare Disorders. Gaucher Disease. NORD Natl Organ Rare Disord. https://rarediseases.org/rare-diseases/gaucher-disease/.
4. NORD. Pompe Disease. NORD Natl Organ Rare Disord. https://rarediseases.org/rare-diseases/pompe-disease/.
5. Burlina AB, Polo G, Salviati L, et al. Newborn screening for lysosomal storage disorders by tandem mass spectrometry in North East Italy. J Inherit Metab Dis. November 2017:1-11. doi:10.1007/s10545-017-0098-3.
6. Li Y, Scott CR, Chamoles NA, et al. Direct Multiplex Assay of Lysosomal Enzymes in Dried Blood Spots for Newborn Screening. Clin Chem. 2004;50(10):1785-1796. doi:10.1373/clinchem.2004.035907.
7. Turgeon CT, Peck DS, Oglesbee D, et al. Precision newborn screening for lysosomal disorders. Genet Med. November 2017:gim2017194. doi:10.1038/gim.2017.194.
Cite This Article:
Coles V., Chan G., Palczewski K., Lewis K., Zhang B., Ho J. The Future of Newborn Screening. Illustrated by W. Zhang. Rare Disease Review. April 2018. DOI:10.13140/RG.2.2.27448.44805.