He studied Developmental Biology at the University of Cambridge as a member of the Wellcome Trust 4-year PhD programme in Developmental Biology. During PhD and post-doctoral studies with Dr Rick Livesey at the Gurdon Institute Dr Sansom used genomic approaches to generate insights into pattern-specification and cell-fate choices in the mammalian neocortex.

Recognising the potential of computational biology in the era of next-generation-sequencing Dr Sansom joined Professor Chris Ponting's Computational Genomics Analysis and Training (CGAT) program as an MRC Career Development Fellow at the University of Oxford in 2011. It was during this time that he developed a strong interest in immunology through collaborative research with Professor Georg Hollander resulting in publication of the first single-cell genomics analysis of promiscuous gene expression in thymic epithelial cells.