GDF6 and microphthalmia: Mutations in MFRP, RPSS56, GDF3, GDF6, CHX10, MCOP1, ALDH1A3, and RAX genes were reported in isolated microphthalmia (9), and isolated microphthalmia could be classified into eight subtypes according to the different mutated variants recorded in the Online Mendelian Inheritance in Man database (OMIM).