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.