FBRSL1, a poorly characterized gene, is a paralogue of AUTS2. Pathogenic mutations in AUTS2, mainly gross deletions, lead to a neurodevelopmental syndrome with autism, microcephaly, short stature, contractures, facial dysmorphism and, in some cases, additional malformations like heart defects (Beunders et al. 2013), demonstrating an overlap to the phenotype observed in our three patients with truncating FBRSL1 variants. This evidence concerns the gene AUTS2 and autism.