Neonatal screening (NBS) was initiated in Europe during the 1960s with the screening for phenylketonuria. The panel of screened disorders (“conditions”) then gradually expanded, with a boost in the late 1990s with the introduction of tandem mass spectrometry (MS/MS), making it possible to screen for 40–50 conditions using a single blood spot. The most recent additions to screening programmes (screening for cystic fibrosis, severe combined immunodeficiency and spinal muscular atrophy) were assisted by or realised through the introduction of molecular technologies. For this survey, we collected data from 51 European countries. We report the developments between 2010 and 2020 and highlight the achievements reached with the progress made in this period. We also identify areas where further progress can be made, mainly by exchanging knowledge and learning from experiences in neighbouring countries. Between 2010 and 2020, most NBS programmes in geographical Europe matured considerably, both in terms of methodology (modernised) and with regard to the panel of conditions screened (expanded). These developments indicate that more collaboration in Europe through European organisations is gaining momentum. We can only accomplish the timely detection of newborn infants potentially suffering from one of the many rare diseases and take appropriate action by working together.

The cyclic adenosine monophosphate (cAMP) intracellular signaling pathway mediates the physiological effects of several hormones and neurotransmitters, acting by the activation of G-protein coupled receptors (GPCRs) and several downstream intracellular effectors, including the heterotrimeric stimulatory G-protein (Gs), the cAMP-dependent protein kinase A (PKA), and cAMP-specific phosphodiesterases (PDEs). Defective G-protein-mediated signaling has been associated with an increasing number of disorders, including Albright hereditary osteodistrophy (AHO) and pseudohypoparathyroidism (PHP), a heterogeneous group of rare genetic metabolic disorders resulting from molecular defects at the GNAS locus. Moreover, mutations in PRKAR1A and PDE4D genes have been recently detected in patients with acrodysostosis (ACRDYS), showing a skeletal and endocrinological phenotype partially overlapping with AHO/PHP. Despite the high detection rate of molecular defects by currently available molecular approaches, about 30% of AHO/PHP patients still lack a molecular diagnosis, hence the need to screen patients negative for GNAS epi/genetic defects also for chromosomal regions and genes associated with diseases that undergo differential diagnosis with PHP. According to the growing knowledge on Gsa-cAMP signaling-linked disorders, we investigated our series of patients (n ¼ 81) with a clinical diagnosis of PHP/AHO but negative for GNAS anomalies for the presence of novel genetic variants at PRKAR1A and PDE4D genes. Our work allowed the detection of 8 novel missense variants affecting genes so far associated with ACRDYS in 9 patients. Our data further confirm the molecular and clinical overlap among these disorders. We present the data collected from a large series of patients and a brief review of the literature in order to compare our findings with already published data; to look for PRKAR1A/PDE4D mutation spectrum, recurrent mutations, and mutation hot spots; and to identify specific clinical features associated with ACRDYS surveillance during follow-up.

Objective: Thyroid dyshormonogenesis is a genetically heterogeneous group of inherited disorders in the enzymatic cascade of thyroid hormone synthesis that result in congenital hypothyroidism (CH). Thyroid peroxidase gene (TPO) mutations are one of the most common causes of thyroid dyshormonogenesis. The aim of this study was to identify TPO gene defects in a cohort of patients with thyroid dyshormonogenesis from Slovenia, Bosnia, and Slovakia. Design and methods: Forty-three patients with permanent CH and orthoptic thyroid glands from 39 unrelated families participated in the study. Mutational analysis of the TPO gene and part of its promoter consisted of single-stranded conformation polymorphism analysis, sequencing, and restriction fragment length polymorphism (RFLP) analysis. Results: TPO gene mutations were identified in 46% of participants. Seven different mutations were identified, four mutations of these being novel, namely 613COT (R175X), 1519_1539del (A477_N483del), 2089GOA (G667S), and 2669GOA (G860R). Only a single allele mutation was identified in 65% of the TPO mutation carriers. Conclusions:The results showed a higher prevalence of TPO gene mutations in thyroid dyshormonogenesis when compared with published studies. The high percentage of single allele mutations implied possible intronic or regulatory TPO gene mutations or monoallelic expression.

Mutations in FGFR1 have recently been associated with Hartsfield syndrome, a clinically distinct syndromic form of holoprosencephaly (HPE) with ectrodactly, which frequently includes combinations of craniofacial, limb and brain abnormalities not typical for classical HPE. Unrelated clinical conditions generally without craniofacial or multi-system malformations include Kallmann syndrome and idiopathic hypogonadotropic hypogonadism. FGFR1 is a principal cause for these less severe diseases as well. Here we demonstrate that of the nine FGFR1 mutations recently detected in our screen of over 200 HPE probands by next generation sequencing, only five distinct mutations in the kinase domain behave as dominant-negative mutations in zebrafish over-expression assays. Three FGFR1 mutations seen in HPE probands behave identical to wild-type FGFR1 in rescue assays, including one apparent de novo variation. Interestingly, in one HPE family, a deleterious FGFR1 allele was transmitted from one parent and a loss-of-function allele in FGF8 from the other parent to both affected daughters. This family is one of the clearest examples to date of gene:gene synergistic interactions causing HPE in humans.

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