Evaluation of Optineurin as a candidate gene in Indian patients with primary open angle glaucoma.

PURPOSE To evaluate the role of the optineurin gene (OPTN) in Indian primary open angle glaucoma (POAG) patients from different parts of the country. METHODS Two hundred patients with POAG and 200 ethnically matched normal controls were recruited from various parts of India for the study. The entire coding region of OPTN along with the intron-exon boundaries were screened by PCR and single strand conformation polymorphism (SSCP) followed by direct sequencing. A rapid screening method was developed for some of the observed variants by denaturing high performance liquid chromatography (dHPLC). Four variants were also confirmed by digesting the amplicon with appropriate restriction enzymes. RESULTS Seven nucleotide changes were observed in OPTN of which one was a putative mutation in exon 16 (Arg545Gln) that was observed in six POAG patients and not in the controls (p<0.05). The remaining variants comprised four single nucleotide polymorphisms (SNPs) in the coding region (Thr34Thr, Met98Lys, Arg149Arg, and Asn303Lys) and two in intron 6 (879-10G>A and 879-5C>T). But frequencies of the minor allele were not significantly different among the patients and controls. The Met98Lys variant that was identified to be a potential risk factor for NTG and POAG in some Asian populations and also for modulating IOP in Caucasian populations, did not exhibit any significant association to the disease phenotype. CONCLUSIONS Despite a putative mutation (Arg545Gln) in some patients, the present study does not suggest a significant involvement of OPTN in POAG patients of Indian origin.