A common variant near TGFBR3 is associated with primary open angle glaucoma

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/ licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited.Primary open angle glaucoma (POAG), a major cause of blindness worldwide, is a complex disease with a significant genetic contribution.We performed Exome Array (Illumina) analysis on 3504 POAG cases and 9746 controls with replication of the most significant findings in 9173 POAG cases and 26 780 controls across 18 collections of Asian, African and European descent. Apart from confirming strong evidence of association at CDKN2B-AS1 (rs2157719 [G], odds ratio [OR] = 0.71, P = 2.81 × 10−33), we observed one SNP showing significant association to POAG (CDC7–TGFBR3 rs1192415, ORG-allele = 1.13, Pmeta = 1.60 × 10−8). This particular SNP has previously been shown to be strongly associated with optic disc area and vertical cup-to-disc ratio, which are regarded as glaucoma-related quantitative traits. Our study now extends this by directly implicating it in POAG disease pathogenesis

A common variant near TGFBR3 is associated with primary open angle glaucoma

Primary open angle glaucoma (POAG), a major cause of blindness worldwide, is a complex disease with a significant genetic contribution. We performed Exome Array (Illumina) analysis on 3504 POAG cases and 9746 controls with replication of the most significant findings in 9173 POAG cases and 26 780 controls across 18 collections of Asian, African and European descent. Apart from confirming strong evidence of association at CDKN2B-AS1 (rs2157719 [G], odds ratio [OR] = 0.71, P = 2.81 × 10−33), we observed one SNP showing significant association to POAG (CDC7–TGFBR3 rs1192415, ORG-allele = 1.13, Pmeta = 1.60 × 10−8). This particular SNP has previously been shown to be strongly associated with optic disc area and vertical cup-to-disc ratio, which are regarded as glaucoma-related quantitative traits. Our study now extends this by directly implicating it in POAG disease pathogenesis

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Abstract Primary open angle glaucoma (POAG), a major cause of blindness worldwide, is a complex disease with a significant genetic contribution. We performed Exome Array ), we observed one SNP showing significant association to POAG (CDC7-TGFBR3 rs1192415, OR G-allele = 1.13, P meta = 1.60 × 10 −8 ). This particular SNP has previously been shown to be strongly associated with optic disc area and vertical cup-to-disc ratio, which are regarded as glaucoma-related quantitative traits. Our study now extends this by directly implicating it in POAG disease pathogenesis

Screening for mutation hotspots in Bardet–Biedl syndrome patients from India

Background & objectives: Bardet–Biedl syndrome (BBS) is a genetically heterogeneous autosomal recessive disorder characterized by multiple organ defects involving retina, kidney, liver and brain. Disease-causing mutations in BBS genes narrowed down by homozygosity mapping in small consanguineous and non-consanguineous pedigrees were reported in 80 per cent of the study population. This study was aimed to screen these genes (BBS3, BBS10) and specific exons of BBS genes (BBS1, BBS5, MKKS, BBS9, BBS11 and BBS12) for recurrent mutations in a selected sample of BBS patients. Methods: The recurrent mutations in BBS genes were screened in the BBS affected individuals by PCR based direct sequencing. The pathogenicity of the observed mutations were confirmed by co-segregation analysis, screening of healthy unrelated controls and in silico analysis. Results: In the 64 BBS patients (44 males, 20 females) were studied, mutations were predominant in BBS10 and ARL6 genes; the c.272T>C; p.(I91T) mutation in ARL6 gene was a recurrent mutation. One novel non-sense mutation c.425T>G; p(L142FNx01) was obtained in BBS5 gene (family BSI-31). Interpretation & conclusions: BBS10 gene mutations clustered in exon 2 of the gene suggesting the exon as a probable hotspot for mutations in Indian population. A cost- and time-effective strategy for the molecular diagnosis of BBS was designed based on these results

Genetic testing in four Indian families with suspected Stickler syndrome

Purpose: Stickler syndrome is associated with the development of rhegmatogenous retinal detachment (RRD), and often presents with ocular, auditory, skeletal, and orofacial abnormalities. Molecular analysis has proven effective in diagnosis, confirmation and classification of the disease. We aimed to describe the utility of next-generation sequencing (NGS) in genetic analysis of four Indian families with suspected Stickler syndrome. Methods: The index cases presented with retinal detachment with family history. Genetic analysis in the index case was performed by next-generation sequencing of inherited retinal degeneration genes, and validated by Sanger sequencing followed by co-segregation analysis in the other family members. Results: Twenty patients were included for the genetic analysis (15 males and 5 females from four families). Clinical details were available for 15 patients (30 eyes). Fourteen eyes (11 patients) developed RRD. In the 16 eyes without RRD, 8 underwent barrage laser to lattice degeneration and 8 were under observation. Disease segregating heterozygous mutations with pathogenic/likely pathogenic effect was identified in COL2A1 (c.4318-1G>A, c.141G>A, c.1221+1G>A for 3 families) and COL11A1 (c.1737+1 G>A for 1 family) gene. In addition to the mutation in the COL2A1 gene, a pathogenic heterozygous variant associated with risk for arrhythmogenic right ventricular cardiomyopathy (ARVC) was identified in one member. Conclusion: NGS testing confirmed the presence of the causative gene for Stickler syndrome in the index case followed by evaluation of family members and confirmation of genetic and ocular findings. We believe that this may be the first such report of families with RRD from India

High-throughput genetic analysis in a cohort of patients with Ocular Developmental Anomalies

Anophthalmia and microphthalmia (A/M) are developmental ocular malformations in which the eye fails to form or is smaller than normal with both genetic and environmental etiology. Microphthalmia is often associated with additional ocular anomalies, most commonly coloboma or cataract [1, 2]. A/M has a combined incidence between 1-3.2 cases per 10,000 live births in Caucasians [3, 4]. The spectrum of genetic abnormalities (chromosomal and molecular) associated with these ocular developmental defects are being investigated in the current study. A detailed pedigree analysis and ophthalmic examination have been documented for the enrolled patients followed by blood collection and DNA extraction. The strategies for genetic analysis included chromosomal analysis by conventional and array based (affymetrix cytoscan HD array) methods, targeted re-sequencing of the candidate genes and whole exome sequencing (WES) in Illumina HiSEQ 2500. WES was done in families excluded for mutations in candidate genes. Twenty four samples (Microphthalmia (M)-5, Anophthalmia (A)-7,Coloboma-2, M&A-1, microphthalmia and coloboma / other ocular features-9) were initially analyzed using conventional Geimsa Trypsin Geimsa banding of which 4 samples revealed gross chromosomal aberrations (deletions in 3q26.3-28, 11p13 (N=2) and 11q23 regions). Targeted re sequencing of candidate genes showed mutations in CHX10, PAX6, FOXE3, ABCB6 and SHH genes in 6 samples. High throughput array based chromosomal analysis revealed aberrations in 4 samples (17q21dup (n=2), 8p11del (n=2)). Overall, genetic alterations in known candidate genes are seen in 50% of the study subjects. Whole exome sequencing was performed in samples that were excluded for mutations in candidate genes and the results are discussed

Genetic Association of SNPs near <i>ATOH7</i>, <i>CARD10</i>, <i>CDKN2B</i>, <i>CDC7</i> and <i>SIX1/SIX6</i> with the Endophenotypes of Primary Open Angle Glaucoma in Indian Population

<div><p>Primary open angle glaucoma (POAG) belonging to a group of optic neuropathies, result from interaction between genetic and environmental factors. Study of associations with quantitative traits (QTs) is one of the successful strategies to understand the complex genetics of POAG. The current study attempts to explore the association of variations near/in genes like <i>ATOH7</i>, <i>SIX1/SIX6</i> complex, <i>CDKN2B</i>, <i>CARD10</i>, and <i>CDC7</i> with POAG and its QTs including vertical cup to disc ratio (VCDR), central corneal thickness (CCT), intra ocular pressure (IOP), and axial length (AL). Case-control study design was carried out in a sample size of 97 POAG cases and 371 controls from South India. Model-based (additive, recessive, dominant) association of the genotypes and their interaction was carried out between cases and controls using chi-square, linear and logistic regression methods. Nominal significance (<i>P</i><0.05) was observed for QTs like i) VCDR with SNPs rs1900004 (<i>ATOH7</i>); rs1192415 (<i>CDC7)</i>; rs10483727 (<i>SIX1/SIX6)</i>, rs9607469 (<i>CARD10);</i> ii) CCT with rs1192415; iii) IOP with rs1900004 and iv) AL with rs1900004 and rs1063192 (<i>CDKN2B)</i>. We were able to replicate previously known interactions between <i>ATOH7-SIX6</i> and <i>SIX6-CDKN2B</i> along with few novel interactions between <i>ATOH7</i>—<i>CDC7</i> and <i>SIX6</i> with genes including <i>CARD10</i> and <i>CDC7</i>. In summary, our results suggest that a probable interaction among the candidate genes for QTs, play a major role in determining the individual’s susceptibility to POAG.</p></div

Multiple linear regression analysis for the SNPs with AL, CCT, VCDR and IOP as dependant variable in the whole cohort.

<p>^Ω = <i>P(</i>β± SE)</p><p>β = standard regression coefficient; SE = standard error; AL-axial length; CCT- Central corneal thickness, VCDR-vertical cup to disc ratio, IOP- intra ocular pressure.</p><p>*Obtained from linear regression, adjusted for age and gender</p><p>Bonferroni adjusted significant level< = 0.008 (0.05/6). Variation in no of samples depends on the availability of data.</p><p>Multiple linear regression analysis for the SNPs with AL, CCT, VCDR and IOP as dependant variable in the whole cohort.</p

Analysis of minor allele frequencies and χ^<b>2</b> of the SNPs between POAG and controls.

<p>M- Major allele, m-minor allele</p><p>* <i>P</i> values are derived from χ² tests; significance: P<0.05</p><p>Analysis of minor allele frequencies and χ^<b>2</b> of the SNPs between POAG and controls.</p

Demographic and clinical features of the study subjects.

<p>*the age at recruitment for controls or age of disease onset for POAG patients are shown</p><p>SD-standard deviation, IOP- intraocular pressure, VCDR-vertical cup to disc ratio, CCT- central corneal thickness, AL- axial length, ACD- anterior chamber depth.</p><p>Demographic and clinical features of the study subjects.</p