Glaucoma, a complex heterogenous disease, is the leading cause for optic nerve–related blindness worldwide. Since 1997, when mutations in the myocilin (MYOC) gene were identified as causing juvenile onset as well as a proportion of primary open-angle glaucoma (POAG), more than 180 variants have been documented. Approximately one in 30 unselected patients with POAG have a disease-causing myocilin mutation and it has been shown that firm genotype–phenotype correlations exist. We have compiled an online catalog of myocilin variants and their associated phenotypes. This locus-specific resource, to which future submissions can be made, is available online (www.myocilin.com; last accessed 28 August 2007). The database, constructed using MySQL, contains three related sheets that contain data pertaining to the information source, variant identified, and relevant study data, respectively. The website contains a list of all identified variants and summary statistics as well as background genomic information, such as the annotated sequence and cross-protein/species homology. Phenotypic data such as the mean±standard deviation (SD) age at POAG diagnosis, mean±SD maximum recorded intraocular pressure, proportion of patients requiring surgical intervention, and age-related penetrance can be viewed by selecting a particular mutation. Approximately 40% of the identified sequence variants have been characterized as disease causing, with the majority (∼85%) of these being missense mutations. Preliminary data generated from this online resource highlight the strong genotype–phenotype correlations associated with specific myocilin mutations. The large-scale assimilation of relevant data allows for accurate comprehensive genetic counseling and the translation of genomic information into the clinic. Hum Mutat 29(2), 207–211, 2008. © 2007 Wiley-Liss, Inc.