CSTB and progressive myoclonus epilepsy: It is still unclear how different types of progressive myoclonus epilepsies can have synergistic mechanisms since mutations in two other genes, PRICKLE1 (Prickle planar cell polarity protein 1) and SCARB2 (Scavenger receptor class B member 2), have been reported in patients with symptoms closely resembling EPM1 (Bassuk et al, 2008; Dibbens et al, 2009).