PAX6 and microphthalmia: The occurrence of germinal or gonosomal mosaicism was suspected in 2 of the 3 families as the most plausible factor to explain either the unusual recurrence of PAX6-related microphthalmia in the offspring of a healthy couple (Family 3, Figure 1C), or the remarkable inter-generational phenotypic variability between a proband and her father (Family 2, Figure 1B), respectively.