Primary open-angle glaucoma is a complex of ocular disorders characterized by irreversible lesions of the optic nerve, open angle of the anterior chamber of the eye and elevated intraocular pressures. GLC1A, a locus involved in one form of this disease, has been mapped to an approximately 9-cM interval within 1q23-q25, between markers D1S445 and D1S416/D1S480. A 10-cM yeast artificial chromosome (YAC) contig spanning the whole region is described. This contig is based on 67 YACs, and 41 sequence tagged sites comprising 23 genetic markers, 16 YAC ends and 2 expressed sequence tags. The reagents reported in this study should be useful tools for the identification of the GLC1A gene by positional cloning.