PhD, Genetics, Yale University (2014)
Postdoctoral Research Associate, State Lab, Yale University (2007-2011)
Membership of the Royal College of Paediatrics and Child Health, UK (2007)
Bachelor of Medicine; Bachelor of Surgery (BMBS); Nottingham University Medical School, UK (2003)
Stephan trained as a pediatric physician at Nottingham and London in the UK before undertaking a PhD and postdoctoral research position at Yale. His research focuses on using genomics and bioinformatics to understand the etiology of human disease, especially ASD.
Using SNP genotyping arrays on samples in the Simons Simplex Collection, he clarified the important role of de novo copy number variation (CNVs) in ASD, which included the discovery of duplications at 7q11.23; this finding is of note since deletions at the same locus cause Williams-Beuren syndrome, which is associated with increased sociability. In the same sample cohor, he used exome sequencing to show that de novo loss of function (LoF) mutations are associated with ASD and to establish a statistical framework for identifying the specific genes involved in ASD pathology based on these de novo events. This statistical method was used to identify the gene SCN2A and has since identified multiple ASD genes with high confidence.
Most recently, Stephan has worked with a group of collaborators to investigate what these ASD genes can reveal about ASD neuropathology. By integrating spatiotemporal gene expression data from the human brain (BrainSpan) and the results of exome sequencing, the group built and interrogated spatiotemporal co-expression networks to identify points of convergence in gene expression. This approach has highlighted the role of layer 5/6 glutamatergic neurons in the frontal cortex in mid-fetal development in the causation of ASD.