Summary Autism Spectrum Disorder (ASD) affects roughly 1% of the world’s population, and currently there are no mechanism-based treatments that address the core features of ASD. It is now clear that the genetics underlying ASD are complex; with several hundreds of genes conferring large risk as well as common variants contributing to a large proportion of ASD heritability. Genetic studies of ASD suggest a high degree of convergence on specific cellular processes and biochemical pathways, which have led researchers to posit that potential therapeutic strategies may be shared across different genetic etiologies. The study of monogenic or syndromic forms of ASD has been a leading strategy to gain insight into the complex mechanisms of ASD. Fragile X Syndrome (FXS) is among the leading monogenic causes of ASD and is the most common inherited cause of intellectual disability. Since the Fragile X gene (FMR1) was cloned in 1991, the field has used cellular assays and model organisms to elucidate the functions of the FMR1 protein (FMRP), the consequences of its loss and identify therapeutic targets for FXS and ASD. Other syndromic forms of ASD, such as tuberous sclerosis complex, Rett Syndrome, Angelman Syndrome, and others, are being investigated using similar approaches. Recent technological advances in stem-cell derived neurons, single cell sequencing, gene therapy, human neurons and organoids are setting the stage for transformative advances in therapeutic development for these neurodevelopmental disorders. This conference will bring together leading basic and translational scientists studying ASD, Fragile X and related neurodevelopmental disorders from around the world with the ultimate goal of developing mechanism-based treatments that address the core features of these diseases.