PRSS56 mutations are a major cause of nanophthalmos, characterized by severe shortening of ocular axial length and high hyperopia (Gal et al., 2011; Nair et al., 2011; Orr et al., 2011), and polymorphisms at PRSS56 have been previously reported to be associated with RE and myopia (Kiefer et al., 2013; Verhoeven et al., 2013; Hysi et al., 2020), angle-closure glaucoma (Nair et al., 2011; Jiang et al., 2013), and ocular abnormalities in humans and mice (Labelle-Dumais et al., 2020; Siggs et al., 2020). Here, PRSS56 is linked to microphthalmia.