Disclosed is a gene sensitive to a normal-tension glaucoma disease. Also disclosed is a method for utilizing the gene. Comprehensive analysis/comparison was made on single nucleotide polymorphisms on the entire genome in many normal-tension glaucoma patients and many normal persons, and it is found that there is a difference in polymorphism sites found in ELOVL5-containing regions on human chromosome-6 and the like among the patients and the normal persons, wherein the polymorphism sites are represented by the international single nucleotide polymorphism numbers rs222450, rs9474394, rs2816344, rs2816341, rs2518579, rs2518578, rs9367511, rs6915699, rs6930045, rs9370188, rs9382180, rs9382181, rs4486010, rs2816379, rs6939730, rs2817088, rs2817090, rs2816372, rs2562895, rs2816364, rs2562893, rs2817101, rs2816362, rs2816356, rs10948744, rs12183976, rs2562898, rs735860, rs715441, rs2057024, rs1429146, rs9463895, rs2235723, rs1346603, rs9474476, rs2294867, rs9349660, rs974323, rs6909592, rs9367520, rs9395854, rs209485, rs9395856, rs7747926, rs7738788, rs209500, rs9357760, rs9370196, rs209512, rs209517, rs9370201, rs9367529, rs12209741, rs7744451, rs6904083, rs6904376, rs9367532, rs2067833, rs9382212, rs2139077, rs2397146, rs7742367, rs9474576, rs622447, rs3736729, rs13212365 and rs761141. It becomes possible to diagnose normal-tension glaucoma based on the difference in those polymorphism sites.