HLA-DRB and HLA-DQB loci in the genetic susceptibility to develop glaucoma in Mexicans

Glaucoma is a clinically heterogeneous disease with a pathophysiology that may include genetic susceptibility, possibly associated with an immunologic disorder. The aim of this study was to determine whether the DNA polymorphisms located in the HLA-DRB1 and HLA-DQB1 genes show a specific association pattern in Mexican mestizo patients with primary open-angle glaucoma.

This was a cross-sectional, case-control, multicenter study. We analyzed the HLA-DRB1 and DQB1 loci of 81 Mexican mestizo nonrelated patients with primary open-angle glaucoma and 98 healthy ethnic matched control subjects. Patients were diagnosed clinically and by visual fields examination. HLA typing was performed by PCR-SSO reverse dot blot.

We documented increased frequencies of HLA-DRB1*0301, DRB1*1101, DRB1*0701, DRB1*1402, DQB1*0302, and DQB1*0301; however, none of them were significantly different from normal control subjects. Haplotype analysis showed that the HLA-DRB1*0407-DQB1*0302 haplotype is significantly increased in patients compared with control subjects (P = .0001).

The haplotype HLA-DRB1*0407-DQB1*0302 is common among Mexican mestizo (haplotype frequency = 0.102), and it was increased in our patients (haplotype frequency = 0.259, P = .0001). This may reflect an independent association of this haplotype with the disease as the result of linkage disequilibrium or the influence of a neighboring gene. The pathophysiology of this illness is uncertain, and further studies are needed regarding the genetic susceptibility to develop primary open-angle glaucoma.