Part of the missense variants contribute to isolated FH and are mostly located in CTS, while those contribute to aniridia, microphthalmia, anophthalmia, and coloboma are mainly located in NTS [11, 19]. The missense variants could cause differences in DNA binding, protein folding, and the transactivation activities of PAX6 [1, 11]. This evidence concerns the gene PAX6 and microphthalmia.