TMEM98 and microphthalmia: Nanophthalmos can be caused by genes other than TMEM98. In fact, the first nanophthalmos locus (NNO1) was mapped in 1998 [8], and last year, using the same family, Garnai and colleagues reported in PLOS Genetics that the underlying cause was a mutation in MYRF that leads to a C-terminal truncation [9].