This gene encodes a secreted protein with a cystein-knot motif that activates the Wnt/beta-catenin pathway. The protein forms disulfide-linked oligomers in the extracellular matrix. Mutations in this gene result in Norrie disease and X-linked exudative vitreoretinopathy. [provided by RefSeq, Feb 2009] see less This gene encodes a secreted protein with a cystein-knot motif that activates the Wnt/beta-catenin pathway. The protein forms disulfide-linked oligomers in the extracellular matrix. Mutations in this gene result in Norrie disease and X-linked exudative vitreoretinopathy. [provided by RefSeq, Feb 2009]