CYP1B1 Gene and Phenotypic Correlation in Patients From Northeastern Brazil With Primary Congenital Glaucoma.

PURPOSE: To identify variants in the CYP1B1 gene in northeastern Brazilian patients with primary congenital glaucoma (PCG) and possible genotype-phenotype correlations. MATERIALS AND METHODS: This is a cross-sectional observational study of 17 nonrelated patients with PCG, performed at the Altino Ventura Foundation, Recife, Brazil, between December 2017 and February 2018. All patients underwent an examination, including gathering information from their medical records, slit-lamp examination, fundoscopy, tonography, and measuring corneal diameter and thickness. RESULTS: The mean age at the time of the examination was 27.7 years; 52.9% (n=9) were male, 29.4% (n=5) had history of parental consanguinity. The mean age when the diagnosis was confirmed was 0.53±2.18 years. Horizontal corneal diameter ranged from 12 to 16 mm (mean: 14.05±1.42 mm) and the IOP mean value was 17.31±9.84 mm Hg. Predicted pathogenic variants of the CYP1B1 gene were identified in 4 patients (23.5%). The differences among all clinical parameters did not reach statistical significance between individuals with and without CYP1B1 variants (P-values >0.05). CONCLUSIONS: Two variants which had not been previously related to PCG in Brazil (c.182G>A, c.241T>A) were identified. No statistically significant genotype-phenotype correlations were found.

The p53 codon 72 PRO/PRO genotype may be associated with initial central visual field defects in caucasians with primary open angle glaucoma.

BACKGROUND: Loss of vision in glaucoma is due to apoptotic retinal ganglion cell loss. While p53 modulates apoptosis, gene association studies between p53 variants and glaucoma have been inconsistent. In this study we evaluate the association between a p53 variant functionally known to influence apoptosis (codon 72 Pro/Arg) and the subset of primary open angle glaucoma (POAG) patients with early loss of central visual field. METHODS: Genotypes for the p53 codon 72 polymorphism (Pro/Arg) were obtained for 264 POAG patients and 400 controls from the U.S. and in replication studies for 308 POAG patients and 178 controls from Australia (GIST). The glaucoma patients were divided into two groups according to location of initial visual field defect (either paracentral or peripheral). All cases and controls were Caucasian with European ancestry. RESULTS: The p53-PRO/PRO genotype was more frequent in the U.S. POAG patients with early visual field defects in the paracentral regions compared with those in the peripheral regions or control group (p=2.7 × 10(-5)). We replicated this finding in the GIST cohort (p  =7.3 × 10(-3), and in the pooled sample (p=6.6 × 10(-7)) and in a meta-analysis of both the US and GIST datasets (1.3 × 10(-6), OR 2.17 (1.58-2.98 for the PRO allele). CONCLUSIONS: These results suggest that the p53 codon 72 PRO/PRO genotype is potentially associated with early paracentral visual field defects in primary open-angle glaucoma patients.

Lack of association of polymorphisms in elastin with pseudoexfoliation syndrome and glaucoma.

PURPOSE: To evaluate the elastin gene (ELN) as a secondary risk factor for pseudoexfoliation syndrome (PXFS) and the associated glaucoma pseudoexfoliation glaucoma (PXFG). METHODS: One hundred seventy-eight unrelated patients with PXFS, including 132 patients with PXFG, and 113 unrelated controls were recruited from the Massachusetts Eye and Ear Infirmary. All the patients and controls were white of European ancestry. Three tag SNPs (rs2071307, rs3823879, and rs3757587) that capture the majority of alleles in ELN were genotyped. Single-SNP association was analyzed using Fisher exact test. Haplotype analysis and the set-based test were used to assess the association for the whole gene. Interaction analysis was done between the ELN SNP rs2071307 and LOXL1 SNP rs2165241 using logistic regression. Multiple comparisons were corrected using the Bonferroni method. RESULTS: All 3 ELN tag SNPs were not significantly associated with PXFS and PXFG (P>0.20). The minor allele frequencies in PXFS, PXFG, and controls were 40.7%, 39.8%, and 45.6%, respectively for rs2071307, 6.7%, 6.3%, and 5.4% for rs3823879, and 14.8%, 16.2%, and 13.6% for rs3757587. Haplotype analysis and the set-based test did not find significant association of ELN with PXFS (P=0.94 and 0.99, respectively). No significant interaction effects on PXFS were identified between the ELN and LOXL1 SNPs (P=0.55). CONCLUSIONS: Our results suggest that common polymorphisms of ELN are not associated with PXFS and PXFG in white populations. Further studies are required to identify secondary genetic factors that contribute to PXFS.