Lack of association between p53 gene polymorphisms and primary open angle glaucoma in the Japanese population

PURPOSE To assess whether tumor protein p53 gene (p53) polymorphisms are associated with primary open angle glaucoma (POAG) in the Japanese population. METHODS Four hundred and twenty-five Japanese patients with POAG, including normal tension glaucoma (NTG, n=213) and high tension glaucoma (HTG, n=212) and 189 control subjects without glaucoma were analyzed for two p53 polymorphisms (rs1042522; a G-->C substitution at codon 72 in exon 4 and rs59758982; a 16 base pair insertion in intron 3) using allele specific primer PCR and a pyrosequencing technique respectively. The genotypic and allelic frequencies were compared between NTG or HTG patients and control subjects. RESULTS No significant difference (NTG versus control, p=0.99, and HTG versus control, p=0.69, chi(2) test) was observed regarding the p53 genotype frequencies at codon 72 between the NTG (GG: 43.2%, GC: 44.6%, CC: 12.2%) or HTG (GG: 40.1%, GC: 48.1%, CC: 11.8%) patients and the control subjects (GG: 43.9%, GC: 43.9%, CC: 12.2%). In addition, there was no significant difference (NTG versus control, p=0.94; and HTG versus control, p=0.66, Fisher's exact test) in the p53 allele frequencies at codon 72 between the NTG (G allele: 65.5%, C allele: 34.5%) or HTG (G allele: 64.2%, C allele: 35.8%) patients and the control subjects (G allele: 65.9%, C allele: 34.1%). No 16 base pair insertion in intron 3 was found in this study. CONCLUSION p53 polymorphisms were not associated with POAG in the Japanese population. Further studies in the other ethnic populations should therefore be performed to elucidate whether the p53 intron 3 insertion polymorphism is a genetic risk factor for POAG, because the intron 3 insertion polymorphism occurs very rarely in the Japanese population.