The SysNDD database is based on its predecessor database, SysID (, previously: It contains a manually curated catalogue of published genes implicated in neurodevelopmental disorders (NDDs) and classified into primary and candidate genes according to the degree of underlying evidence.

Furthermore, manually curated information on associated diseases and phenotypes is provided. To allow interoperability and mapping between gene-, phenotype- or disease-oriented databases, we center our approach around curated gene-inheritance-disease units, so called entities. SysNDD is updated every 3-4 months and can be utilized for a broad spectrum of tasks from both research and diagnostics.

One of our long-term goals is to incorporate the SysID / SysNDD data into other gene/disease-relationship databases like the Orphanet ontology.

SysID was initially conceived by Annette Schenck (Radboud University Center Nijmegen, the Netherlands) and Christiane Zweier (Department of Human Genetics at the University/ University Hospital Bern, Switzerland; previously: Institute for Human Genetics, University Hospital Erlangen), FAU Erlangen-Nürnberg, Germany). SysNDD has been built and is maintained by Christiane Zweier and Bernt Popp (senior physician at the Berlin Institute of Health (BIH) at Charité, Germany and scientist at the Institute of Human Genetics at the University Hospital Leipzig, Germany). CZ has been involved in establishing and updating SysID from its start in 2009. She is performing and coordinating curation and updates. BP developed and programmed the new SysNDD database and will be integrating further functionality including associated variants and network analyses in future updates.

SysNDD database website