Laboratory diagnostics in inborn errors of metabolism

Background Inborn errors of metabolism are frequently due to a gene defect, which impairs or disrupts the function of an enzyme, thus affecting a certain step in a metabolic pathway. Early diagnosis and start of treatment without delay are often of decisive importance for the developmental perspectives of affected patients. Methods Newborn screening, selective screening and specific tests for the laboratory diagnostics of metabolic disorders are presented. Results While neonatal screening is indiscriminately performed for all newborns, selective screening and specific tests are individually chosen and conducted only for selected patients. Conclusion Although mutation analyses are becoming increasingly more relevant in the laboratory diagnostics of inborn errors of metabolism, investigations on metabolites and enzyme levels remain important for the clarification of a suspected diagnosis.