No other likely candidate gene was identified in the targeted analysis of the exomes; in particular no disease-causing variant in any of the known congenital myasthenic syndrome (CMS) genes (RAPSN, CHRNE, AGRN, ALG2, CHAT, CHRNA1, CHRNB1, CHRND, CHRNE, COLQ, DOK7, GFPT1, GMPPB, MUSK, PREPL and SLC5A7) was found. Here, CHRND is linked to congenital myasthenic syndrome.