MBTPS1 and Atypical behavior: Interestingly, dysregulation of ceramides, alkaline ceramidases and S1P have been implicated in neurodegenerative disorders, indicating the potentially altered sphingolipids in RXLI may contribute to the behavioural disorders associated with RXLI (Cutler et al., 2004; Ben-David and Futerman, 2010; Wang et al., 2015).