Four loci for nanophthalmos, i.e., NNO1 for autosomal dominant (Othman et al. 1998), NNO2 for autosomal recessive (Sundin et al. 2005), NNO3 for autosomal dominant (Li et al. 2008), and NNO4 for autosomal dominant (Awadalla et al. 2014), have been mapped, in which mutations in MFRP are responsible for NNO2 while those in TMEM98 are responsible for NNO4. The gene discussed is MFRP; the disease is microphthalmia.