Multiple gene polymorphisms analysis revealed a different profile of genetic polymorphisms of primary open-angle glaucoma in northern Chinese

Purpose: To evaluate the individual and interactive effects of polymorphisms in the myocilin (MYOC), optineurin (OPTN), WD repeat domain 36 (WDR36), and apolipoprotein E (APOE) genes on primary open-angle glaucoma (POAG) in northern Chinese. Methods: Northern Chinese study subjects, 176 POAG patients and 200 controls, were recruited for screening of the coding exons and splicing regions of MYOC. Five single nucleotide polymorphisms (SNPs) in OPTN (M98K, R545Q, IVS5+38T>G, IVS8-53T>C, and IVS15+10G>A), one SNP in WDR36 (IVS5+30C>T) as well as the APOE promoter and epsilon 2/epsilon 3/epsilon 4 polymorphisms were also examined. Association analysis was performed by using chi(2) analysis. High-order gene-gene interaction was also analyzed using the multifactor dimensionality reduction (MDR) method. Results: In MYOC, 22 variants were identified. Four of them were novel but found in controls only. The missense mutation, Val53Ala, is likely a glaucoma causing mutation, accounting for 0.6% of cases. No individual polymorphism in OPTN, WDR36, or APOE was associated with POAG. MDR analysis identified a best 6-factor model for POAG: MYOC IVS2+35A>G, OPTN Met98Lys, OPTN IVS5+38T>G, OPTN IVS8-53T>C, WDR36 IVS5+30C>T, and APOE -491A>T. Conclusions: The association pattern between the genes, MYOC, OPTN, WDR36, and APOE, and POAG in northern Chinese is different from that of southern Chinese. Disease-causing mutations in MYOC accounted for a small proportion of northern Chinese POAG patients. Common polymorphisms in these genes were not associated with POAG individually but might interactively contribute to the disorder, supporting a polygenic etiology.Biochemistry & Molecular BiologyOphthalmologySCI(E)20ARTICLE9-1189-981

AC and AG Dinucleotide Repeats in the PAX6 P1 Promoter are Associated with High Myopia

Purpose: The PAX6 gene, located at the reported myopia locus MYP7 on chromosome 11p13, was postulated to be associated with myopia development. This study investigated the association of PAX6 with high myopia in 379 high myopia patients and 349 controls. Methods: High myopia patients had refractive errors of –6.00 diopters or greater and axial length longer than 26 mm. Control subjects had refractive errors less than –1.00 diopter and axial length shorter than 24 mm. The P1 promoter, all coding sequences, and adjacent splice-site regions of the PAX6 gene were screened in all study subjects by polymerase chain reaction and direct sequencing. PAX6 P1 promoter-luciferase constructs with variable AC and AG repeat lengths were prepared and transfected into human ARPE-19 cells prior to assaying for their transcriptional activities. Results: No sequence alterations in the coding or splicing regions showed an association with high myopia. Two dinucleotide repeats, (AC)m and (AG)n, in the P1 promoter region were found to be highly polymorphic and significantly associated with high myopia. Higher repeat numbers were observed in high myopia patients for both (AC)m (empirical p = 0.013) and (AG)n (empirical p = 0.012) dinucleotide polymorphisms, with a 1.327-fold increased risk associated with the (AG)n repeat (empirical p = 0.016; 95% confidence interval: 1.059–1.663). Luciferase-reporter analysis showed elevated transcription activity with increasing individual (AC)m and (AG)n and combined (AC)m(AG)n repeat lengths. Conclusions: Our results revealed an association between high myopia and AC and AG dinucleotide repeat lengths in the PAX6 P1 promoter, indicating the involvement of PAX6 in the pathogenesis of high myopia

A Cohesin Subunit Variant Identified from a Peripheral Sclerocornea Pedigree

Background: Sclerocornea is a rare congenital disorder characterized with the opacification of the cornea. Here, we report a nonconsanguineous Chinese family with multiple peripheral sclerocornea patients spanning across three generations inherited in an autosomal dominant manner. Methods: This is a retrospective case series of a peripheral sclerocornea pedigree. Comprehensive ophthalmic examinations were conducted and assessed on 14 pedigree members. Whole-exome sequencing was used to identify the genetic alterations in the affected pedigree members. Lymphoblastoid cell lines (LCLs) were established using blood samples from the family members. Functional tests were performed with these cell lines. Results: Six affected and eight unaffected members of a family with peripheral sclerocornea were examined. All affected individuals showed features of scleralization over the peripheral cornea of both eyes. Mean horizontal and vertical corneal diameter were found significantly decreased in the affected members. Significant differences were also observed on the mean apex pachymetry between affected and unaffected subjects. These ophthalmic parameters did not resemble that of cornea plana. A RAD21(C1348T) variant was identified by whole-exome sequencing. Although this variant causes RAD21 R450C substitution at the separase cleavage site, cells from peripheral sclerocornea family members had no mitosis and ploidy defects. Conclusion: We report a family of peripheral sclerocornea with no association with cornea plana. A RAD21 variant was found cosegregating with peripheral sclerocornea. Our results suggest that RAD21 functions, other than its cell cycle and chromosome segregation regulations, could underline the pathogenesis of peripheral sclerocornea