Taking previously published patients into account, the number of individuals with SYN1-related neurodevelopmental disorders for whom clinical information is available is 83 (71 males and 12 females; Table 1) (Garcia et al. 2004; Fassio et al. 2011; Nguyen et al. 2015; Guarnieri et al. 2017; Peron et al. 2018; Fernandez-Marmiesse et al. 2019; Darvish et al. 2020; Ibarluzea et al. 2020; Accogli et al. 2021; Mojarad et al. 2021; van der Ven et al. 2021; Xiong et al. 2021; Yang et al. 2020; Zhou et al. 2021). Here, SYN1 is linked to neurodevelopmental disorder.