NR2F1 and Bosch-Boonstra-Schaaf optic atrophy syndrome: NR2F1 mutations are responsible for the Bosch-Boonstra-Schaaf optic atrophy syndrome (OMIM #615722; BBSOAS), whereas SOX2 mutations cause micro- or anophtalmia (OMIM #206900, Microphtalmia, syndromic 3; optic nerve hypoplasia and abnormalities of the central nervous system).