Selective Metabolic Screening from a Neonatology Perspective

Metabolic diseases are quite rare diseases when considered alone, but they are affecting approximately 1:3.000–4.000 of live births when considering the cumulative meaning. Particularly considering that diseases are inherited genetically, “screening programs for metabolic disease” is very important for those aiming people not only live but also quality to live. Screening feasible in neonates can be analyzed in two groups such as general screening and selective screening tests. The general screening tests are further divided into Newborn Metabolic Screening Program and Expanded Newborn Screening. As a large part of metabolic diseases do not affect the baby at birth, all live-born neonates without any clinical findings are implemented in the process of screening programs at a proper time. This application is called as “Newborn Metabolic Screening Program”, and it is made considering the reality of each country with different diseases and limit values. Tandem mass spectrometry (Tandem MS/MS) can not take place in a national screening programme; although a very expensive analytical instrument, the testing is cost-effective because screening of more than 30 diseases is possible with one drop of blood. This practice has been widespread since the last 15 years defined as “Expanded Newborn Screening”. Newborns with a positive family history for metabolic disease (defined as metabolic disease or death from a metabolic disease in the family) and/ or neonates with clinical symptoms suggestive of metabolic diseases; implementation of selected tests for targeted metabolic disease or metabolic disease group considered as “Selective Metabolic Screening Tests”. This is, usually, a strategy carried out in developing countries. The aim is to get a clue to define the maximum number of possible metabolic diseases in the shortest period that can lead to serious problems. On the other hand, it should be known that if the “selective screening test is negative”, it does not mean “there is no disease’’. Newborn metabolic screening tests performed for the early recognition of inherited metabolic diseases is basically a public health service. Considering this aspect, it is not only a laboratory service but also an integration of systems including education, data assessment, diagnosis, treatment, and long-term management approach. (JAREM 2015; 5: 39-46)