Iodine intake monitoring in neonatal population in the Czech Republic: alarming numbers in 2020.

Thanks to comprehensive and long-term preventive programs, the Czech Republic has taken its place among the countries with a resolved iodine deficiency at all population levels since 2004. A sensitive indicator of iodine supply to the population, which can also be used to monitor the efficiency of prophylactic programs, is the TSH assessment in the nationwide neonatal screening of congenital hypothyroidism. Nevertheless, recent results of neonatal TSH show that newborns and pregnant women remain very risky groups and their iodine saturation is borderline. In recent years, the percentage of newborns with TSH 5-15 mIU/l has already risen above the 3% mark, i.e. mild iodine deficiency in major part of the Czech Republic (3.8 % in Bohemia, 2.8% in Moravia in 2019 and 4.7 % in Bohemia, 2.9% in Moravia in 2020). For some smaller areas, the values are even higher, which can be related, for example, to the social patterns of the population. The result may be not only the exclusion of the Czech Republic from the list of countries with resolved iodine deficiency, but especially adverse consequences for the cognitive development of the future generation. Therefore, it is essential to intensify nation-wide intervention among both the professional and general public. In this regard, adherence to the supplementation of pregnant and breastfeeding women is crucial with 150-200 μg of iodide in addition to nutritional iodine intake.

Epidemiology of rare diseases detected by newborn screening in the Czech Republic.

OBJECTIVES: Presymptomatic detection of patients with rare diseases (RD), defined by a population frequency less than 1 : 2,000, is the task of newborn screening (NBS). In the Czech Republic (CZ), currently eighteen RD are screened: phenylketonuria/hyperphenylalaninemia (PKU/HPA), congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH), cystic fibrosis (CF), medium chain acyl-CoA dehydrogenase deficiency (MCADD), long chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD), very long chain acyl-CoA dehydrogenase deficiency (VLCADD), carnitine palmitoyl transferase I and II deficiency (CPTID, CPTIID), carnitine-acylcarnitine translocase deficiency (CACTD), maple syrup urine disease (MSUD), glutaric aciduria type I (GA I), isovaleryl-CoA dehydrogenase deficiency (IVA), argininemia (ARG), citrullinemia (CIT), biotinidase deficiency (BTD), cystathionine beta-synthase-deficient homocystinuria (CBSD HCU), and methylenetetrahydrofolate reductase deficiency homocystinuria (MTHFRD HCU). The aim was to analyze the prevalence of RD screened by NBS in CZ. METHODS: We examined the NBS programme in CZ from 1 January 2010 to 31 December 2017, which covered 888,891 neonates. Dried blood spots were primarily analyzed using fluorescence immuno-assay, tandem mass spectrometry and fluorimetry. RESULTS: The overall prevalence of RD among the neonate cohort was 1 : 1,043. Individually, 1 : 2,877 for CH, 1 : 5,521 for PKU/HPA, 1 : 6,536 for CF (1 : 5,887 including false negative patients), 1 : 12,520 for CAH, 1 : 22,222 for MCADD, 1 : 80,808 for LCHADD, 1 : 177,778 for GA I, 1 : 177,778 for IVA, 1 : 222,223 for VLCADD, 1 : 296,297 for MSUD, 1 : 8,638 for BTD, and 1 : 181,396 for CBSD HCU. CONCLUSIONS: The observed prevalence of RD, based on NBS, corresponds to that expected, more precisely it was higher for BTD and lower for MSUD, IVA, CBSD HCU, MCADD and VLCADD. Early detection of rare diseases by means of NBS is an effective secondary prevention tool.