Although several CMS subtypes such as slow-channel syndrome (Chaouch et al., 2012), DOK7-CMS (Müller et al., 2007) and GFPT1-CMS (Guergueltcheva et al., 2011) can have mildly raised creatine kinase values, this is rare (apart from in GFPT1-CMS, not seen in over 300 CMS cases analysed in Oxford), and when reported has rarely been more than two to three times normal values. The gene discussed is DOK7; the disease is congenital myasthenic syndrome.