Impact of expanded newborn screening in the identification of hereditary diseases in two Italian regions (Piemonte e Valle d’Aosta)|Screening neonatale esteso di malattie ereditarie rare: l’esperienza del Piemonte e della Valle d’Aosta

Newborn screening (NBS) is the most effective tool for the identification of serious health conditions as it allows early diagnosis and prompt treatment initiation. The screening center of Torino carries out screening for newborns from two Italian regions (Piemonte and Valled’Aosta) for Phenylketonuria (PKU), Congenital Hypothyroidism (CH), Galactosemia (GAL), Biotinidase deficiency (BTD), Cystic Fibrosis (CF), 36 Inborn Errors of Metabolism and Congenital Adrenal Hyperplasia (CAH). Expanded NBS (NBSE, Italian Law 167/2016) should be performed on all live births between 48-72 hours of life. Since May 2017, 165 758 Dried Blood Spots were analyzed by time-resolved Immunofluorescence (Galactose, Biotinidase, Immunoreactive Trypsinogen, 17-hydroxy-Progesterone, Thyroid Stimulating Hormone), or by tandem mass spectrometry (simultaneous quantification of aminoacids and acylcarnitines). 378 diagnosis were made: 153 CH (42.5%); 88 CF (23.3%); 54 aminoacidopathies (14.3%); 29 BTD (7.7%); 24 fatty acid oxidation disorders (6.3%); 14 GAL (3.7%); 9 CAH (2.4%); 4 organic acidemias (1.1%); 3 urea cycle disorders (0.7%). Moreover, another five conditions have been identified: 237 heterozygous subjects; 108 subjects with transient impairment; 31 subjects with impairment acquired from maternal deficiency; 15 patients needed to continue the process of a differential diagnosis of the screened pathologies; 5 patients with acute neonatal onset of diseases not covered by the law. During this activity, the overall incidence of early diagnoses was of 1:438 newborns. The majority of these screening-positive newborns suffered from diseases with a high degree of risk of progression for which immediate therapeutic intervention and the adoption of preventive measures were required.