Analysis of SMOC2 gene variants in familial and nonfamilial primary open angle glaucoma Pakistani patients

AIM:To find out the association of secreted protein acidic and rich in cysteine(SPARC)-related modular calcium binding 2(SMOC2)gene variants rs2255680 and rs13208776 with genotypic and phenotypic characteristics in both familial and non-familial primary open angle glaucoma(POAG)patients.METHODS:A total of 212 POAG patients,comprising 124 familial and 88 non-familial,were enrolled.For genotyping the SMOC2 variant rs2255680,amplification refractory mutation system(ARMS)-polymerase chain reaction(PCR)method and PCR-restriction fragment length polymorphism(PCR-RFLP)were utilized for analyzing rs13208776 variant.RESULTS:The mean age of familial POAG patients was 50.92±9.12y,with 78 males and 46 females.The mean age of non-familial POAG patients was 53.14±13.44y,with 52 males and 36 females.The SMOC2 gene variant rs13208776 showed the significant association with POAG between familial and non-familial groups.The homozygous G/G variant was frequent among non-familial(60.2%)whereas the heterozygous G/A variant was more frequent in familial POAG patients(46%).There were significant differences in G/A variant between familial and non-familial glaucoma patients,and the risk was decreased to 0.53-fold in non-familial glaucoma patients[odds ratio(OR):0.53;95%confidence interval(CI):0.29-0.94;P=0.033]in codominant model.The risk was further reduced to 0.49-fold(95%CI:0.28-0.86;P=0.012)in dominant model for non-familial patients.No significant association of SMOC2 gene variant rs2255680 between familial and non-familial glaucoma patients was found in our population.The haplotype analysis showed the decreased risk for TA[OR:0.48(95%CI:0.29-0.79);P=0.004]and an increased risk for TG[OR=2.28(95%CI:1.22-4.25);P=0.01]haplotypes.CONCLUSION:Current findings show significant association of SMOC2 gene variant rs13208776 with POAG between familial and non-familial Pakistani patients.