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Abstract #18542 Published in IGR 3-3
Targeted disruption of the myocilin gene (Myoc) suggests that human glaucoma-causing mutations are gain of function
Kim BS; Savinova OV; Reedy MV; Martin J; Lun Y; Gan L; Smith RS; Tomarev SI; John SWM; Johnson RLMolecular and Cellular Biology 2001; 21: 7707-7713
Glaucoma is a heterogeneous eye disease and a major cause of blindness worldwide. Recently, primary open angle glaucoma (POAG)-associated mutations have been found in the trabecular meshwork inducible glucocorticoid response gene (TIGR), also known as the myocilin gene (MYOC), at the GLC1A locus on chromosome 1q21-q31. These mutations occurred in a subset of patients with juvenile- and adult-onset POAG and exhibited autosomal dominant inheritance. Ocular expression and its involvement in POAG suggest that TIGR/MYOC may have a role(s) in regulating intraocular pressure (IOP). Here, the authors report the generation and analysis of mice heterozygous and homozygous for a targeted null mutation in Myoc. The study shows that Myoc mutant mice are both viable and fertile. The in vivo findings further demonstrate that Myoc is not required for normal IOP or normal ocular morphology. The lack of a discernable phenotype in both Myoc-heterozygous and Myoc-null mice suggests that haplo-insufficiency is not a critical mechanism for POAG in individuals with mutations in MYOC. Instead, disease-causing mutations in humans likely act by gain of function.
Dr R.L. Johnson, Department of Biochemistry, University of Texas, M.D. Anderson Cancer Center, Houston, TX 77030, USA. rjohnson@odin.mdacc.tmc.edu
Classification:
1.2 Population genetics (Part of: 1 General aspects)
