Loss-of-function of one copy of SHANK3 is a known cause of Phelan–McDermid syndrome (PMS), a cause of ASD and intellectual disability (Phelan, 2008; Costales and Kolevzon, 2015; Tachibana et al., 2017; Mitz et al., 2018). Here, SHANK3 is linked to premenstrual tension.