Association of IGF1 polymorphisms with exotropia in a Pakistani cohort.

Purpose: Strabismus (STBMS) is a multifactorial ocular disorder in children that leads to misalignment of the eyes. Insulin-like growth factor 1 (IGF1) has been shown to be involved in the development of extraocular muscles and myopia; however, data are limited on the genetic associations of IGF1 with STBMS in Pakistan. Methods: Two hundred seventy-four STBMS cases and 272 unaffected controls were recruited, and their DNA was extracted. Two IGF1 single nucleotide polymorphisms, rs6214 and rs5742632, were genotyped using PCR-restriction fragment length polymorphism. Univariate logistic regression analysis was performed to determine the association of these single nucleotide polymorphisms with STBMS, and the results were adjusted for age and sex. In addition, 26 extraocular muscle tissues were collected from patients with STBMS undergoing squint correction surgery, along with 3 deceased control samples. IGF1 mRNA expression was measured by quantitative PCR; the Mann-Whitney U test was applied, and fold change was calculated. Logistic regression analysis was applied to determine the association of RNA expression and fold change with genotype. Results: Multivariate logistic regression analysis revealed that rs5742632 (odds ratio [95% confidence interval] = 1.05[1.01-1.06], p = 0.03) is associated with STBM. Moreover, rs6214 (1.03[1.01-1.05], p = 0.03) and rs5742632 (1.09[1.04-1.11], p = 0.04) were associated with exotropia. Statistically, no significant difference in IGF1 mRNA expression in the extraocular muscles between the STBMS cases and the controls was observed. Conclusions: IGF1 polymorphisms rs5742632 (A>G) and rs6214 (C>T) are plausible risk factors for the development of exotropia. However, the physiologic mechanism requires further evaluation.

Mutation screening of the CYP1B1 gene reveals thirteen novel disease-causing variants in consanguineous Pakistani families causing primary congenital glaucoma.

BACKGROUND: Primary congenital glaucoma (PCG) is a heterogeneous rare recessively inherited disorder prevalent in regions with high consanguinity. Disease phenotype is associated with increased intra ocular pressure and is a major cause of childhood blindness. Sequence variations in Cytochrome P450 1B1 (CYP1B1) gene are a major cause of PCG. Current study was conducted to screen CYP1B1 gene in highly consanguineous PCG affected families from Pakistani population consistent with the autosomal recessive pattern of PCG inheritance. METHODS: For this study, patients and controls (clinically unaffected individuals of each family) from 25 consanguineous families belonging to Punjab, Baluchistan and Khyber Pakhtunkhwa, Pakistan were recruited through ophthalmologists. DNA was isolated from collected blood samples. Genetic screening of CYP1B1 gene was done for all enrolled families. In-silico analysis was performed to identify and predict the potential disease-causing variations. RESULTS: Pathogenicity screening revealed sequence variants segregating with disease phenotype in homozygous or compound heterozygous form in eleven out of 25 analyzed families. We identified a total of sixteen disease causing variants among which five frameshift i.e., c.629dup (p.Gly211Argfs*13), c.287dup (p.Leu97Alafs*127), c.662dup (p.Arg222Profs*2), c.758_759insA (p.Val254Glyfs*73) and c.789dup (p.Leu264Alafs*63), two silent c.1314G>A, c.771T>G and six missense variations c.457C>G (p.Arg153Gly), c.516C>A (p.Ser172Arg), c.722T>A (p.Val241Glu), c.740T>A (p.Leu247Gln), c.1263T>A (p.Phe421Leu), and c.724G>C (p.Asp242His) are previously un reported. However two frameshift c.868dup (p.Arg290Profs*37), c.247del (p.Asp83Thrfs*12) and one missense variant c.732G>A (p.Met244Ile), is previously reported. Furthermore, six polymorphisms c.1347T>C, c.2244_2245insT, c.355G>T, c.1294G>C, c.1358A>G and c.142C>G were also identified. In the intronic region, a novel silent polymorphism i.e., g.35710_35711insT was found in homozygous state. All the newly detected disease-causing variants were negative in 96 ethnically matched controls. CONCLUSION: Among twenty-five screened families, eight families (PCG50, 52-54, 58, 59, 63 and 67) were segregating disease causing variants in recessive manner. Two families (PCG049 and PCG062) had compound heterozygosity. Our data confirms genetic heterogeneity of PCG in Pakistani population however we did not find molecular variants segregating with PCG in fifteen families in coding exons and intron-exon boundaries of CYP1B1 gene. Genetic counseling was provided to families to refrain from practicing consanguinity and perform premarital screening as a PCG control measure in upcoming generations.

Targeted gene sequencing of FYCO1 identified a novel mutation in a Pakistani family for autosomal recessive congenital cataract.

BACKGROUND: Congenital cataract is causing one-third of blindness worldwide. Congenital cataract is heterogeneous in its inheritance patterns. The current study is aimed to explore the unknown genetic causes underlying congenital cataracts. METHODS: Blood samples from affected and normal individuals of n = 25 Pakistani families identified with congenital cataracts were collected. Genomic DNA was extracted and Sanger sequencing was performed to identify novel pathogenic variants in the FYCO1 (MIM#607182) gene. Later structural bioinformatics tools and molecular dynamics simulations were performed to analyze the impact of these variants on protein structure and function. RESULTS: Sanger sequencing resulted in the identification of a novel splice site mutation (NM_024513.3: c.3151-29_3151-7del) segregating in an autosomal recessive manner. This novel variant was confirmed to be absent in the n = 300 population controls. Further, bioinformatics tools revealed the formation of a mutant protein with a loss of the Znf domain. In addition, we also found a previously known (c.4127 T > C; p.Leu1376Pro) mutation in four families. We also report a novel heterozygous variant (c.3419G > A; p.Arg1140Gln) in another family. CONCLUSIONS: In conclusion, we report a novel deletion (NM_024513.3: c.3151-29_3151-7del) in one family and a frequent homozygous missense mutation (c.4127 T > C; p.Leu1376Pro) in four Pakistani families. The current research highlights the importance of autophagy in lens development and maintaining its transparency.

Novel mutations in the PITX2 gene in Pakistani and Mexican families with Axenfeld-Rieger syndrome.

PURPOSE: Axenfeld-Rieger syndrome (ARS) is a rare autosomal dominant disorder that affects the anterior segment of the eye. The aim of this study was to examine the PITX2 gene to identify possible novel mutations in Pakistani and Mexican families affected by the ARS phenotype. METHODS: Three unrelated probands with a diagnosis of ARS were recruited for this study. Genomic DNA was isolated from the peripheral blood of the probands and their family members. Polymerase chain reaction and Sanger sequencing were used for the analysis of coding exons and the flanking intronic regions of the PITX2 gene. Bioinformatics tools and database (VarSome, Provean, and MutationTaster, SIFT, PolyPhen-2, and HOPE) were evaluated to explore missense variants. RESULTS: We identified novel heterozygous variations in the PITX2 gene that segregated with the ARS phenotype within the families. The variant NM_153426.2(PITX2):c.226G > T or p.(Ala76Ser) and the mutation NM_153426.2(PITX2):c.455G > A or p.(Cys152Tyr) were identified in two Pakistani pedigrees, and the mutation NM_153426.2(PITX2):c.242_265del or p.(Lys81_Gln88del), segregated in a Mexican family. CONCLUSION: Our study extends the spectrum of PITX2 mutations in individuals with ARS, enabling an improved diagnosis of this rare but serious syndrome.

Identification of a Novel ZNF469 Mutation in a Pakistani Family With Brittle Cornea Syndrome.

PURPOSE: Brittle cornea syndrome (BCS) is a rare recessive disorder affecting connective tissues, most prominently in the eye. Pathogenic mutations causing BCS have been identified in PRDM5 and ZNF469 genes. This study investigates the genetic cause of BCS in a large, consanguineous Pakistani family with 4 affected and 3 unaffected individuals. METHODS: The coding region and exon-intron splice junctions of PRDM5 and ZNF469 genes were amplified by polymerase chain reaction, and bidirectional Sanger sequencing was performed to find the pathogenic change responsible for causing the disease in the family. RESULTS: A novel homozygous duplication c.9831dupC (p.Arg3278GlnfsX197) in the ZNF469 gene was identified, which was found to be co-segregating with the disease in the family. CONCLUSIONS: This is the first report of a ZNF469 homozygous mutation causing a BCS phenotype in a consanguineous Pakistani family. Our data extend the mutation spectrum of ZNF469 variants implicated in BCS.

Mutational analysis of the CYP1B1 gene in Pakistani primary congenital glaucoma patients: Identification of four known and a novel causative variant at the 3' splice acceptor site of intron 2.

Primary congenital glaucoma (PCG) causes blindness in early age. It has an autosomal recessive pattern of inheritance, hence is more prevalent in populations with frequent consanguineous marriages that occur in the Pakistani population. Mutations in the CYP1B1 gene are commonly associated with PCG. The aim of the present study was to identify genetic mutations in the CYP1B1 gene in PCG cases belonging to 38 Pakistani families. DNA was extracted using blood samples collected from all enrolled patients, their available unaffected family members and controls. Direct sequencing of the CYP1B1 gene revealed a novel 3' splice acceptor site causative variant segregating in an autosomal recessive manner in a large consanguineous family with four PCG-affected individuals. The novel variant was not detected in 93 ethnically matched controls. Furthermore, four already reported mutations, including p.G61E, p.R355X, p.R368H, and p.R390H were also detected in patients belonging to nine different families. All identified causative variants were evaluated by computational programs, that is, SIFT, PolyPhen-2, and MutationTaster. Pathogenicity of the novel splice site variant identified in this study was analyzed by Human Splicing Finder and MaxEntScan. Ten out of 38 families with PCG had the disease due to CYP1B1 mutations, suggesting CYP1B1 was contributing to PCG in these Pakistani patients. Identification of this novel 3' splice acceptor site variant in intron 2 is the first report for the CYP1B1 gene contributing to genetic heterogeneity of disease.

Anisometropia and refractive status in children with unilateral congenital nasolacrimal duct obstruction.

OBJECTIVE: The objective of the study was to evaluate the refractive status and thereby assess anisometropia in children with unilateral congenital nasolacrimal duct obstruction (CNLDO). STUDY DESIGN: This study design was a descriptive cross-sectional study. PLACE AND DURATION: this study was conducted at the Department of Pediatric Ophthalmology and Strabismology, Al-Shifa Trust Eye Hospital, Rawalpindi; from August 2013 to July 2014. METHODOLOGY: This study assessed consecutive children with unilateral CNLDO. Cycloplegic refraction on all children with CNLDO was performed followed by appropriate intervention. Refractive errors of the affected and normal eyes were compared. RESULTS: One hundred and twenty-four children with a mean age of 29.69 ± 21.12 months (range, 2 months to 8 years) were studied. Based on spherical equivalent (SE), hypermetropia was more common in the affected eyes (P < 0.001). Anisometropia of >1.5 diopters (D) was present in n = 17 (13.7%). Interocular difference was significant for spherical error and SE (P < 0.001) but not cylindrical errors. CONCLUSION: Unilateral CNLDO is associated with statistically significant anisometropia, especially anisohypermetropia which has amblyogenic potential. It is vital to perform cycloplegic refraction routinely and counsel parents regarding prognosis and regular follow-ups.

Anisometropia and Refractive Status in Children with Bilateral Congenital Nasolacrimal Duct Obstruction.

OBJECTIVE: To evaluate the state of refraction in children with bilateral congenital nasolacrimal duct obstruction (CNLDO). STUDY DESIGN: Descriptive study. PLACE AND DURATION OF STUDY: Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan, from April 2014 to April 2016. METHODOLOGY: Children with bilateral CNLDO were studied. Patients' refractive status were evaluated by performing cycloplegic refraction, followed by appropriate management plan. The refractive errors of both eyes were noted and compared for any significant anisometropia. RESULTS: One hundred and seventeen (n=117) children with median age (IQR) of 32 (12) months having bilateral CNLDO were enrolled. Children with bilateral CNLDO had insignificant interocular difference in terms of spherical equivalent (SE) and cylindrical refractive errors (p>0.05). The rate of the anisometropia (>1 D difference between the two eyes) was 5.98% (n=7) in children with bilateral CNLDO. CONCLUSION: Performing cycloplegic refraction routinely in patients with bilateral CNLDO is not as urgent as compared to ones with unilateral CNLDO. Further, avoidance of early surgical intervention in children with bilateral CNLDO will spare the parents from the emotional trauma and positively influence the health economics worldwide.

Delineation of Novel Autosomal Recessive Mutation in GJA3 and Autosomal Dominant Mutations in GJA8 in Pakistani Congenital Cataract Families.

Congenital cataract is a clinically and genetically heterogeneous disease. The present study was undertaken to find the genetic cause of congenital cataract families. DNA samples of a large consanguineous Pakistani family were genotyped with a high resolution single nucleotide polymorphism Illumina microarray. Homozygosity mapping identified a homozygous region of 4.4 Mb encompassing the gene GJA3. Sanger sequence analysis of the GJA3 gene revealed a novel homozygous variant c.950dup p.(His318ProfsX8) segregating in an autosomal recessive (AR) manner. The previously known mode of inheritance for GJA3 gene mutations in cataract was autosomal dominant (AD) only. The screening of additional probands (n = 41) of cataract families revealed a previously known mutation c.56C>T p.(Thr19Met) in GJA3 gene. In addition, sequencing of the exon-intron boundaries of the GJA8 gene in 41 cataract probands revealed two additional mutations: a novel c.53C>T p.(Ser18Phe) and a known c.175C>G p.(Pro59Ala) mutation, both co-segregating with the disease phenotype in an AD manner. All these mutations are predicted to be pathogenic by in silico analysis and were absent in the control databases. In conclusion, results of the current study enhance our understanding of the genetic basis of cataract, and identified the involvement of the GJA3 in the disease etiology in both AR and AD manners.

Variants in the PRPF8 Gene are Associated with Glaucoma.

Glaucoma is the cause of irreversible blindness worldwide. Mutations in six genes have been associated with juvenile- and adult-onset familial primary open angle glaucoma (POAG) prior to this report but they explain only a small proportion of the genetic load. The aim of the study is to identify the novel genetic cause of the POAG in the families with adult-onset glaucoma. Whole exome sequencing (WES) was performed on DNA of two affected individuals, and predicted pathogenic variants were evaluated for segregation in four affected and three unaffected Dutch family members by Sanger sequencing. We identified a pathogenic variant (p.Val956Gly) in the PRPF8 gene, which segregates with the disease in Dutch family. Targeted Sanger sequencing of PRPF8 in a panel of 40 POAG families (18 Pakistani and 22 Dutch) revealed two additional nonsynonymous variants (p.Pro13Leu and p.Met25Thr), which segregate with the disease in two other Pakistani families. Both variants were then analyzed in a case-control cohort consisting of Pakistani 320 POAG cases and 250 matched controls. The p.Pro13Leu and p.Met25Thr variants were identified in 14 and 20 cases, respectively, while they were not detected in controls (p values 0.0004 and 0.0001, respectively). Previously, PRPF8 mutations have been associated with autosomal dominant retinitis pigmentosa (RP). The PRPF8 variants associated with POAG are located at the N-terminus, while all RP-associated mutations cluster at the C-terminus, dictating a clear genotype-phenotype correlation.

The Genetic Causes of Nonsyndromic Congenital Retinal Detachment: A Genetic and Phenotypic Study of Pakistani Families.

Purpose: To evaluate consanguineous pedigrees from Pakistan with a clinical diagnosis of nonsyndromic congenital retinal nonattachment (NCRNA) and identify genes responsible for the disease as currently only one NCRNA gene is known (atonal basic helix-loop-helix transcription factor 7: ATOH7). Methods: We implemented a three-step genotyping platform: single nucleotide polymorphism genotyping to identify loss of heterozygosity regions in patients, Retinal Information Network panel screening for mutations in currently known retinal genes. Negative patients were then subjected to whole exome sequencing. Results: We evaluated 21 consanguineous NCRNA pedigrees and identified the causal mutations in known retinal genes in 13 out of our 21 families. We found mutations in ATOH7 in three families. Surprisingly, we then found mutations in familial exudative vitreoretinopathy (FEVR) genes; low-density lipoprotein receptor-related protein 5 mutations (six families), tetraspanin 12 mutations (two families), and NDP mutations (two families). Thus, 62% of the patients were successfully genotyped in our study with seven novel and six previously reported mutations in known retinal genes. Conclusions: Although the clinical diagnosis of all children was NCRNA with severe congenital fibrotic retinal detachments, the molecular diagnosis determined that the disease process was in fact a very severe form of FEVR in 10 families. Because severe congenital retinal detachment has not been previously associated with all the FEVR genes, we have thus expanded the phenotypic spectrum of FEVR, a highly variable retinal detachment phenotype that has clinical overlap with NCRNA. We identified seven novel mutations. We also established for the first time genetic overlap between the Iranian and Pakistani populations. We identified eight NCRNA families that do not harbor mutations in any known retinal genes, suggesting novel causal genes in these families.

Tumor Regression Patterns in Retinoblastoma.

OBJECTIVE: To observe the types of tumor regression after treatment, and identify the common pattern of regression in our patients. STUDY DESIGN: Descriptive study. PLACE AND DURATION OF STUDY: Department of Pediatric Ophthalmology and Strabismus, Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan, from October 2011 to October 2014. METHODOLOGY: Children with unilateral and bilateral retinoblastoma were included in the study. Patients were referred to Pakistan Institute of Medical Sciences, Islamabad, for chemotherapy. After every cycle of chemotherapy, dilated fundus examination under anesthesia was performed to record response of the treatment. Regression patterns were recorded on RetCam II. RESULTS: Seventy-four tumors were included in the study. Out of 74 tumors, 3 were ICRB group A tumors, 43 were ICRB group B tumors, 14 tumors belonged to ICRB group C, and remaining 14 were ICRB group D tumors. Type IV regression was seen in 39.1% (n=29) tumors, type II in 29.7% (n=22), type III in 25.6% (n=19), and type I in 5.4% (n=4). All group A tumors (100%) showed type IV regression. Seventeen (39.5%) group B tumors showed type IV regression. In group C, 5 tumors (35.7%) showed type II regression and 5 tumors (35.7%) showed type IV regression. In group D, 6 tumors (42.9%) regressed to type II non-calcified remnants. CONCLUSION: The response and success of the focal and systemic treatment, as judged by the appearance of different patterns of tumor regression, varies with the ICRB grouping of the tumor.

Identification of Novel Variants in LTBP2 and PXDN Using Whole-Exome Sequencing in Developmental and Congenital Glaucoma.

BACKGROUND: Primary congenital glaucoma (PCG) is the most common form of glaucoma in children. PCG occurs due to the developmental defects in the trabecular meshwork and anterior chamber of the eye. The purpose of this study is to identify the causative genetic variants in three families with developmental and primary congenital glaucoma (PCG) with a recessive inheritance pattern. METHODS: DNA samples were obtained from consanguineous families of Pakistani ancestry. The CYP1B1 gene was sequenced in the affected probands by conventional Sanger DNA sequencing. Whole exome sequencing (WES) was performed in DNA samples of four individuals belonging to three different CYP1B1-negative families. Variants identified by WES were validated by Sanger sequencing. RESULTS: WES identified potentially causative novel mutations in the latent transforming growth factor beta binding protein 2 (LTBP2) gene in two PCG families. In the first family a novel missense mutation (c.4934G>A; p.Arg1645Glu) co-segregates with the disease phenotype, and in the second family a novel frameshift mutation (c.4031_4032insA; p.Asp1345Glyfs*6) was identified. In a third family with developmental glaucoma a novel mutation (c.3496G>A; p.Gly1166Arg) was identified in the PXDN gene, which segregates with the disease. CONCLUSIONS: We identified three novel mutations in glaucoma families using WES; two in the LTBP2 gene and one in the PXDN gene. The results will not only enhance our current understanding of the genetic basis of glaucoma, but may also contribute to a better understanding of the diverse phenotypic consequences caused by mutations in these genes.

A Novel Homozygous Mutation in FOXC1 Causes Axenfeld Rieger Syndrome with Congenital Glaucoma.

BACKGROUND: Anterior segment dysgenesis (ASD) disorders are a group of clinically and genetically heterogeneous phenotypes in which frequently cornea, iris, and lens are affected. This study aimed to identify novel mutations in PAX6, PITX2 and FOXC1 in families with anterior segment dysgenesis disorders. METHODS: We studied 14 Pakistani and one Mexican family with Axenfeld Rieger syndrome (ARS; n = 10) or aniridia (n = 5). All affected and unaffected family members underwent full ophthalmologic and general examinations. Total genomic DNA was isolated from peripheral blood. PCR and Sanger sequencing were performed for the exons and intron-exon boundaries of the FOXC1, PAX6, and PITX2 genes. RESULTS: Mutations were identified in five of the 15 probands; four variants were novel and one variant was described previously. A novel de novo variant (c.225C>A; p.Tyr75*) was identified in the PAX6 gene in two unrelated probands with aniridia. In addition, a known variant (c.649C>T; p.Arg217*) in PAX6 segregated in a family with aniridia. In the FOXC1 gene, a novel heterozygous variant (c.454T>C; p.Trp152Arg) segregated with the disease in a Mexican family with ARS. A novel homozygous variant (c.92_100del; p.Ala31_Ala33del) in the FOXC1 gene segregated in a Pakistani family with ARS and congenital glaucoma. CONCLUSIONS: Our study expands the mutation spectrum of the PAX6 and FOXC1 genes in individuals with anterior segment dysgenesis disorders. In addition, our study suggests that FOXC1 mutations, besides typical autosomal dominant ARS, can also cause ARS with congenital glaucoma through an autosomal recessive inheritance pattern. Our results thus expand the disease spectrum of FOXC1, and may lead to a better understanding of the role of FOXC1 in development.

Congenital Cataract, Nasolacrimal Duct Obstruction, and Methicillin-Resistant Staphylococcus aureus Conjunctivitis: When to Operate?

Methicillin-resistant Staphylococcus aureus is one of the toughest organisms to treat, especially in cases where intraocular surgery is contemplated, because the risks are aggravated. Conjunctival swab culture and sensitivity tests are significant when there is history of recent hospitalization. In this report, an infant with successful cataract surgery after elimination of the organism is presented.

Comparison of Anisometropia and Refractive Status in Children With Unilateral and Bilateral Congenital Nasolacrimal Duct Obstruction.

PURPOSE: To evaluate and compare the refractive state in children diagnosed as having unilateral or bilateral congenital nasolacrimal duct obstruction (CNLDO). This study also compares how the laterality of CNLDO affects the refractive state of the patients. METHODS: This descriptive cross-sectional study includes consecutive children with unilateral and bilateral CNLDO over a period of 1 year. Cycloplegic refraction was performed on each child who presented with CNLDO followed by appropriate plans for treatment. The refractive errors of patients with unilateral and bilateral CNLDO were compared. RESULTS: One hundred sixty-one patients with unilateral CNLDO (mean age: 29 ± 19.93 months) and 46 with bilateral CNLDO (mean age: 30 ± 16.21 months) were enrolled from August 2013 to July 2014. The rate of the anisometropia (≥ 1 diopters [D] difference between the two eyes) was 13.7% (n = 22) and 8.6% (n = 4) in patients with unilateral and bilateral CNLDO, respectively. Interocular difference was significant in terms of spherical equivalent (P < .01) but not cylindrical refractive error in patients with unilateral CNLDO. Patients with bilateral CNLDO had insignificant interocular differences in terms of spherical equivalent and cylindrical refractive errors (P > .05). CONCLUSIONS: Unilateral CNLDO is associated with statistically significant anisometropia compared to bilateral CNLDO, which predisposes children with unilateral CNLDO to amblyopia. It is vital to perform cycloplegic refraction routinely and counsel parents regarding regular follow-ups. [J Pediatr Ophthalmol Strabismus. 2016;53(3):168-172.].

Whole exome sequencing identifies a heterozygous missense variant in the PRDM5 gene in a family with Axenfeld-Rieger syndrome.

Axenfeld-Rieger syndrome (ARS) is a disorder affecting the anterior segment of the eye, often leading to secondary glaucoma and several systemic malformations. It is inherited in an autosomal dominant fashion that has been associated with genetic defects in PITX2 and FOXC1. Known genes CYP1b1, PITX2, and FOXC1 were excluded by Sanger sequencing. The purpose of current study is to identify the underlying genetic causes in ARS family by whole exome sequencing (WES). WES was performed for affected proband of family, and variants were prioritized based on in silico analyses. Segregation analysis of candidate variants was performed in family members. A novel heterozygous PRDM5 missense variant (c.877A>G; p.Lys293Glu) was found to segregate with the disease in an autosomal dominant fashion. The novel missense variant was absent from population-matched controls, the Exome Variant Server, and an in-house exome variant database. The Lys293Glu variant is predicted to be pathogenic and affects a lysine residue that is conserved in different species. Variants in the PRDM5 gene were previously identified in anterior segment defects, i.e., autosomal recessive brittle cornea syndrome and keratoconus. The results of this study suggest that genetic variants in PRDM5 can lead to various syndromic and nonsyndromic disorders affecting the anterior segment of the eye.

Variants in the ASB10 Gene Are Associated with Primary Open Angle Glaucoma.

BACKGROUND: Recently nonsynonymous coding variants in the ankyrin repeats and suppressor of cytokine signaling box-containing protein 10 (ASB10) gene were found to be associated with primary open angle glaucoma (POAG) in cohorts from Oregon and Germany, but this finding was not confirmed in an independent cohort from Iowa. The aim of the current study was to assess the role of ASB10 gene variants in Pakistani glaucoma patients. METHODS: Sanger sequencing of the coding exons and splice junctions of the ASB10 gene was performed in 30 probands of multiplex POAG families, 208 sporadic POAG patients and 151 healthy controls from Pakistan. Genotypic associations of individual variants with POAG were analyzed with the Fisher's exact or Chi-square test. RESULTS: In total 24 variants were identified in POAG probands and sporadic patients, including 11 novel variants and 13 known variants. 13 of the variants were nonsynonymous, 6 were synonymous, and 5 were intronic. Three nonsynonymous variants (p.Arg49Cys, p.Arg237Gly, p.Arg453Cys) identified in the probands were not segregating in the respective families. This is not surprising since glaucoma is a multifactorial disease, and multiple factors are likely to be involved in the disease manifestation in these families. However a nonsynonymous variant, p.Arg453Cys (rs3800791), was found in 6 sporadic POAG patients but not in controls, suggesting that it infers increased risk for the disease. In addition, one synonymous variant was found to be associated with sporadic POAG: p.Ala290Ala and the association of the variant with POAG remained significant after correction for multiple testing (uncorrected p-value 0.002, corrected p-value 0.047). The cumulative burden of rare, nonsynonymous variants was significantly higher in sporadic POAG patients compared to control individuals (p-value 0.000006). CONCLUSIONS: Variants in ASB10 were found to be significantly associated with sporadic POAG in the Pakistani population. This supports previous findings that sequence variants in the ASB10 gene may act as a risk factor for glaucoma.

Changes in Central Corneal Thickness and Endothelial Cell Count Following Pediatric Cataract Surgery.

OBJECTIVE: To evaluate the mean changes in Central Corneal Thickness (CCT) and Endothelial Cell Count (ECC) in eyes after pediatric cataract surgery with foldable intraocular lens using scleral tunnel incision micro-surgical technique. STUDY DESIGN: Qausi experimental study. PLACE AND DURATION OF STUDY: Department of Pediatric Ophthalmology and Strabismus, Al-Shifa Trust Eye Hospital, Rawalpindi, from May 2011 to March 2012. METHODOLOGY: Fifty-two eyes of 37 children with pediatric cataract were included in the study. Extracapsular Cataract Extraction (ECE) with foldable Intra Ocular Lens (IOL) implantation using sclera tunnel incision was performed in all children. Endothelial Cell Count (ECC) and Central Corneal Thickness (CCT) were recorded before surgery and 1 month, 3 months and 6 months after surgery and the effect of currently practiced surgical technique on ECC and CCT was evaluated. RESULTS: The mean age at the time of surgery was 8.8 ±2.7 years (range: 4 to 15 years). The postoperative ECC and CCT were significantly different from the pre-operative values. Mean pre-operative ECC was 3175.3 ±218.4 cell/mm2 and in first postoperative month the mean ECC was 3113.4 ±210.8 cell/mm2(p<0.0001). In the 3rd and 6th month postoperative means ECC were 3052 ±202.5 cell/mm2(p<0.0001) and 3015 ±190.6 cell/mm2(p<0.0001), respectively. The mean cell loss at first postoperative month was 1.95% and at 3rd and 6th postoperative month were 3.9% and 5.05%, respectively. Mean pre-operative CCT was 514 ±49.9 µm and first postoperative mean CCT after 1 month was 524.1 ±25 µm (p = 0.084). After the 3rd and 6th months postoperative, mean CCT were 527.3 ±24.6 µm, and 530 ±24.5 µm, respectively. Third and 6th months postoperative means were significantly higher than baseline CCT, p = 0.024 and 0.007, respectively. CONCLUSION: Endothelial cell loss with closed chamber micro-surgical technique using scleral tunnel incision is within acceptable limits and within the range of normal ECC in children.

Fraser Syndrome.

Fraser's Syndrome (FS) is a rare autosomal recessive disorder with a spectrum of malformations. The most consistent features are Cryptophthalmos (CO), syndactyly, genitourinary tract abnormalities, laryngeal and tracheal anomalies, craniofacial dysmorphism, malformations of the ear and nose, orofacial clefting and musculoskeletal defects. FS is genetically heterogeneous; so far mutations in FRAS1, FREM2 and GRIP1 genes have been linked to FS. FS can be diagnosed on clinical examination, pre-natal ultrasound or perinatal autopsy. We present a case of a 3 months old child born to consanguineous healthy parents with bilateral complete CO, unilateral microphthalmia, hypertelorism, syndactyly (hands and feet bilaterally), ambiguous genitalia with cryptorchidism and an umbilical hernia. We also present the criteria for diagnosing FS and the significant features on pre-natal ultrasonography. Around 200 case reports of patients with FS and CO have been published. To our knowledge, this is the first reported case of FS in Pakistan.