Beta 2-adrenergic receptor polymorphism and susceptibility to primary congenital and primary open angle glaucoma.

Objective: It has been shown that arginine to glycine (Arg16Gly), glutamine to glutamic acid (Gln27Glu) and threonine to isoleucine (Thr164Ile) exchanges in codons 16, 27 and 164, respectively, of the beta 2-adrenergic receptor (B2AR) gene significantly alter receptor function. As B2ARs are located on the afferent blood vessels supplying the ciliary body and trabecular meshwork cells, which control aqueous humour dynamics, polymorphisms of B2AR may be involved in the pathophysiology of certain eye diseases, such as glaucoma. Therefore, the aim of the present study was to investigate the distribution of B2AR polymorphisms in patients with primary congenital and primary open angle glaucoma.

Methods: A group of 30 patients with primary congenital glaucoma, 105 with primary open angle glaucoma and 92 control patients were analysed for the Arg16Gly, Gln27Glu, and Thr164IIe polymorphisms of the B2AR by polymerase chain reaction-restriction fragment length polymorphism.

Results: The allelic frequencies of Gly16, Glu27 and IIe164 variant alleles were 66.7, 38.3 and 3.3% in patients with congenital glaucoma, 59.5, 31.0 and 1.0% with glaucoma, and 54.9, 26.6 and 0.5% in controls, respectively. Although statistically non-significant, the frequencies of variant alleles were slightly higher in both groups of the glaucoma patients.

Conclusions: These results suggest no evidence of an association between the Arg16Gly, Glu27Gln and Thr164Ile polymorphisms of the B2AR gene and risk of developing primary open angle glaucoma or primary congenital glaucoma. However, further studies are needed to understand the role of B2AR polymorphisms in patients with eye disease.