Newborn screening programmes in Europe, arguments and efforts regarding harmonisation: Focus on organic acidurias

Background: The state of newborn screening (NBS) programmes for organic acidurias in Europe was assessed by a web-based questionnaire in the EU programme of Community Action in Public Health 2010/2011 among the – at that time – 27 EU member states, candidate countries, potential candidates and three EFTA countries. Results: Thirty-seven data sets from 39 target countries were analysed. Newborn screening for glutaric aciduria type I (GA-I) was performed in ten, for isovaleric aciduria (IVA) in nine and for methylmalonic aciduria including cblA, cblB, cblC and cblD (MMACBL) as well as for propionic aciduria (PA) in seven countries. Samples were obtained at a median age of 2.5 days and laboratory analysis began at median age of 4.5 days. Positive screening results were mostly confirmed in specialised centres by analysis of organic acids in urine. Confirmation of a positive screening result usually did not start before the second week of life (median ages: 9.5 days [IVA], 9 days [GA-I], 8.5 days [PA, MMACBL]) and was completed early in the third week of life (median ages: 15 days [IVA, PA, MMA], 14.5 days [GA-I]). Treatment was initiated in GA-I and IVA at a median age of 14 days and in MMACBL and PA at a median age of 15 days. Conclusion: NBS for organic acidurias in Europe is variable and less often established than for amino acid disorders. While for GA-I its benefit has already been demonstrated, there is room for debate of NBS for IVA and especially PA and MMACBL.