MACF1 and Congenital myasthenic syndromes: However, several additional studies have expanded the phenotypic spectrum associated with MACF1 variants outside the GAR domain to variably include infantile spams and epilepsy16, hypotonia and muscle weakness17, congenital myasthenic syndromes with limb-girdle weakness11,18, non-syndromic hearing loss19, autism spectrum disorder20, structural brain malformations21.