NR2F1 and pathologic nystagmus: In summary, we described two monozygotic twins harboring a novel G105S mutation in NR2F1 DNA binding domain, displaying the classical phenotype of BBSOAS‐affected patients, that is, myoclonic epilepsy in infancy, psychomotor retardation, language delay, vision loss, and nystagmus due to optic nerve atrophy.