Back to Journals » Clinical Ophthalmology » Volume 11

The SPARC-related modular calcium binding protein 2 (SMOC2) gene polymorphism in primary glaucoma: a case-control study

Authors Al-Dabbagh N, Al-Shahrani H, Al-Dohayan N, Mustafa M, Arfin M, Al-Asmari AK

Received 2 November 2016

Accepted for publication 23 December 2016

Published 20 March 2017 Volume 2017:11 Pages 549—555


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 2

Editor who approved publication: Dr Scott Fraser

Najwa Al-Dabbagh,1 Hamoud Al-Shahrani,1 Nourah Al-Dohayan,1 Md Mustafa,2 Misbahul Arfin,2 Abdulrahman K Al-Asmari2

1Department of Ophthalmology, 2Research Center, Prince Sultan Military Medical City, Riyadh, Saudi Arabia

Abstract: Primary glaucomas are among the most common eye diseases that may potentially result in bilateral blindness. Both genetics and environmental factors are reported to be involved in the etiology of primary glaucomas. Secreted protein acidic and rich in cysteine (SPARC)-related modular calcium binding protein 2 (SMOC2) is a matricellular glycoprotein encoded by the SMOC2 gene and known to regulate the expression of extracellular matrix (ECM) proteins and matrix metalloproteinases (MMPs), which play an important role in the pathogenesis of primary glaucomas. The frequencies of alleles and genotypes of SMOC2 variants were examined in 406 Saudi subjects, including primary open angle glaucoma (POAG, n=140) and primary angle closure glaucoma (PACG, n=64) patients and 202 matched healthy controls using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Genotyping of SMOC2 polymorphism (rs13208776) revealed a significantly higher frequency of the heterozygous genotype GA (P<0.01) and a lower frequency of wild type GG genotype (P=0.05) in glaucoma patients compared to the controls. Upon stratification of the patients on the basis of types of glaucoma, PACG patients had a significantly higher frequency of GA genotype as compared to the controls (P<0.01), whereas there was no significant difference between the POAG patient and control groups in frequencies of SMOC2 alleles and genotypes. Further, there was no significant difference in frequency distribution of alleles and genotypes between male and female patients. This study indicates that the GA genotype of SMOC2 (G>A) polymorphism is significantly associated with PACG and may be a risk factor. However, further large-scale studies in the Saudi population as well as in other ethnic populations are needed to confirm this association.

Keywords: glaucoma, SMOC2, polymorphism, genotyping, genetics, Saudi

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]