Since MYOC and CYP1B1 mutations have been observed in the same individual in a few cases, a digenic mode of pathogenesis for glaucoma has sometimes been proposed.15,18 To the best of our knowledge, the CYP1B1 mutation in such patients has always been R368H.15,16 The proposed digenic mode of pathogenesis for PCG should be considered with caution because it is not absolutely clear that the R368H mutation in CYP1B1 actually is a disease associated variation. This evidence concerns the gene CYP1B1 and glaucoma.