Development of diagnostic solutions for neurodevelopmental disorders caused by ubiquitin-proteasome system dysfunction – UPS-NDDiag

Neurodevelopmental disorders (NDDs) represent a heterogeneous group of conditions that persist throughout life, and affect more than 3% of individuals worldwide. NDD has a major impact on the affected individuals, families and society as a whole. Due to high-throughput sequencing, up to 50% of NDD cases are diagnosed as a monogenic cause. Our consortium specifically focuses on pathogenic variants in genes encoding components of the ubiquitin-proteasome system (UPS) associated with NDDs. The UPS ensures the selective degradation of proteins through a complex ubiquitination process involving >1,000 distinct ubiquitin ligases, which prepare these proteins for degradation by the 26S proteasome. The UPS is essential for cellular homeostasis and a vast number of genes are involved, most of them abundantly expressed in brain. It is therefore not surprising that 10-15% of NDDs have been associated with UPS dysfunction. The partners of our UPS-NDDiag consortium have identified more than 250 pathogenic or likely pathogenic variants across >30 UPS genes associated with NDD. However, the complexity of the system causes major challenges in assessing the pathogenicity of genetic variants, and good biomarkers that indicate UPS dysfunction are largely lacking, hampering diagnosis.

Our consortium is structured around six interconnected work packages. These will be addressed by six partners from five countries with complementary skills and outstanding expertise in advanced genetics, functional genomics; facial recognition for diagnosis of rare diseases; functional studies in hIPSCs, Drosophila and mice; bioinformatics; integrative analysis of multi-omics, and pharmaceutical nanotechnology. In addition, 26 international collaborators join the consortium to enrich its knowledge and skills. Our main delivery is to provide reliable biomarkers and functional assays to classify UPS-related variants. Besides, UPS-NDDiag will yield therapeutic targets that may support drug development for personalized medicine and shed light on our current understanding of the overall pathogenesis of disorders related to the UPS.