Correction: Loss of the BMP Antagonist, SMOC-1, Causes Ophthalmo-Acromelic (Waardenburg Anophthalmia) Syndrome in Humans and Mice.

[This corrects the article DOI: 10.1371/journal.pgen.1002114.].

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.

Identification of novel CYP1B1 gene mutations in patients with primary congenital and primary open-angle glaucoma.

BACKGROUND: CYP1B1 is the most commonly mutated gene in primary congenital glaucoma (PCG), and mutations have also been identified in primary open-angle glaucoma (POAG). This study was undertaken to describe mutations in CYP1B1 in patients and families with PCG and POAG from Pakistan. DESIGN: Case-control series. PARTICIPANTS: Forty families, 190 sporadic POAG cases and 140 controls from Pakistan. METHODS: Patients and healthy individuals of one consanguineous Pakistani family were genotyped with high-resolution single nucleotide polymorphism microarrays. Homozygosity mapping was performed using HomozygosityMapper. Direct sequencing of CYP1B1 gene was performed in probands of the families, sporadic POAG cases and control individuals. MAIN OUTCOME MEASURES: Mutations in the CYP1B1 gene in PCG and POAG patients. RESULTS: Homozygosity mapping in a consanguineous Pakistani family revealed one 11-Mb homozygous region encompassing the CYP1B1 gene. A homozygous CYP1B1 missense mutation (p.Arg390His) was identified in this family. Sequence analysis of CYP1B1 in 39 additional families revealed one known and three novel homozygous mutations in PCG (p.Ala288Pro, p.Asp242Ala, p.Arg355* and p.Arg290Profs*37). In POAG, one novel heterozygous missense mutation (p.Asp316Val) was identified in one family and a previously reported mutation (p.Glu229Lys) was identified in three families. Analysis of CYP1B1 in a panel of 190 sporadic POAG patients revealed three novel heterozygous variants (p.Thr234Lys, p.Ala287Pro and p.Gln362*) and three previously reported heterozygous variants (p.Gly61Glu, p.Glu229Lys and p.Arg368His). The p.Glu229Lys variant was significantly associated with POAG (P = 0.03; odds ratio 2.49). CONCLUSIONS: This study confirms that CYP1B1 mutations are associated with POAG and PCG in the Pakistani population.

Loss of the BMP antagonist, SMOC-1, causes Ophthalmo-acromelic (Waardenburg Anophthalmia) syndrome in humans and mice.

Ophthalmo-acromelic syndrome (OAS), also known as Waardenburg Anophthalmia syndrome, is defined by the combination of eye malformations, most commonly bilateral anophthalmia, with post-axial oligosyndactyly. Homozygosity mapping and subsequent targeted mutation analysis of a locus on 14q24.2 identified homozygous mutations in SMOC1 (SPARC-related modular calcium binding 1) in eight unrelated families. Four of these mutations are nonsense, two frame-shift, and two missense. The missense mutations are both in the second Thyroglobulin Type-1 (Tg1) domain of the protein. The orthologous gene in the mouse, Smoc1, shows site- and stage-specific expression during eye, limb, craniofacial, and somite development. We also report a targeted pre-conditional gene-trap mutation of Smoc1 (Smoc1(tm1a)) that reduces mRNA to ∼10% of wild-type levels. This gene-trap results in highly penetrant hindlimb post-axial oligosyndactyly in homozygous mutant animals (Smoc1(tm1a/tm1a)). Eye malformations, most commonly coloboma, and cleft palate occur in a significant proportion of Smoc1(tm1a/tm1a) embryos and pups. Thus partial loss of Smoc-1 results in a convincing phenocopy of the human disease. SMOC-1 is one of the two mammalian paralogs of Drosophila Pentagone, an inhibitor of decapentaplegic. The orthologous gene in Xenopus laevis, Smoc-1, also functions as a Bone Morphogenic Protein (BMP) antagonist in early embryogenesis. Loss of BMP antagonism during mammalian development provides a plausible explanation for both the limb and eye phenotype in humans and mice.

Duane's syndrome: surgical outcome and non ophthalmologic associations.

BACKGROUND: Duane retraction syndrome (DRS) is the most common of the ocular congenital cranial dysinnervation disorders .This study evaluates the types of Duane syndrome and its management in patients presenting to the paediatric and strabismus unit of a tertiary care eye hospital. METHODS: This case series study involved 41 patients diagnosed with Duane syndrome between January 2007 and December 2009. History of presenting complaints, past treatment and family history were recorded. Ocular examination and orthoptic assessment was carried out RESULTS: Forty one patients were included in this case series study. It involved 10 right eyes, 27 left eyes and both eyes of 4 patients. There were 26 females and 15 males. Type-1 Duane syndrome was present in 28 (68.3%), type 2 in 8 (19.5%), Type-3 in 4 (9.8%) and type-4 with synergistic divergence was present in 1 (2.4%) patient. Comorbidity was present in 6(14.6%) patients. Surgery was carried out in 26 (63.4%) patients either for  abnormal head posturing or significant upshoots or down shoots. Upshoots noted in 21 eyes, were completely or partially resolved in 15 cases. Among 4 patients with down shoots on adduction, complete resolution was seen in 1. The pre and post-operative measurements of horizontal deviation showed statistically significant difference in Duane type-1 and 2, where as in Duane type-3 it was not significant. One patient with type-4 Duane did not undergo surgery. CONCLUSIONS: Recession of the horizontal recti is more effective in treating the upshoot or down shoot associated with DRS as compared to recession and y-split of the horizontal muscle.

Outcome of surgical treatment of monocular elevation deficiency.

OBJECTIVE: To assess the outcome of surgical treatment in patients with monocular elevation deficiency. METHODS: This prospective study included 36 patients of monocular elevation deficiency surgically treated from January 2006 to June 2009, at a tertiary care eye hospital in Rawalpindi, Pakistan. Corrected visual acuity, refractive error, ocular examination, orthoptic assessment and ptosis evaluation were recorded. Strabismus surgery was performed according to the results of forced duction test (FDT). Ptosis surgery, if required, was performed after the strabismus surgery. Patients having any restrictive cause or previous strabismus surgery were excluded. The study conformed to all local laws and was compliant with the principles of the Declaration of Helsinki and had the approval of the Hospital Ethics Committee. RESULTS: The 36 patients were treated surgically and completed the required follow-up. The forced duction test was positive for inferior rectus (IR) of the involved eye in 20 of the 36 eyes (55.55%). Twelve patients had inferior rectus recession with or without one horizontal muscle recession or resection, 12 had Knapp procedure correcting for any horizontal deviation if present, 10 had inferior rectus recession followed by Knapp surgery, with or without recession or resection of horizontal recti, 1 patient had horizontal correction only, while one patient had ptosis correction only without squint surgery. Of the 36 patients, 33 had post-operative (PO) hypotropia within 10 prism diopters (PD). Three patients developed consecutive hypertropia. CONCLUSION: Careful pre-operative evaluation can lead to satisfactory cosmetic improvement after surgery in monocular elevation deficiency. The forced duction test should be performed in both eyes so that any associated oblique muscle laxity (OML) can be noted.

A case of systemic lupus erythematosus with aplastic anaemia.

Systemic lupus erythematosus is an autoimmune disorder, which has a rare association with aplastic anaemia. A young 26 years old lady who presented with a history of intermittent fever, microcytic anaemia, joint pains and mild degree of splenomegaly was investigated. Bone marrow examination showed aplasia. Serological tests revealed positive antinuclear antibody and anti double-stranded DNA tests. Patient was diagnosed as having aplastic anaemia with Systemic lupus erythematosus, managed with steroids and being followed up for monitoring the response.

Vein of Galen aneurysmal malformation masquerading as carotid cavernous fistula in a child with proptosis.

PURPOSE: An infant with proptosis and dilated episcleral vessels was diagnosed with vein of Galen malformation, which is a rare condition presenting initially to an ophthalmologist. METHODS: An 8-month-old child presented with slowly progressive proptosis of the left eye of 5 months' duration. The proptosis was axial, nonpulsatile, with no associated bruit. Dilated corkscrew episcleral vessels were observed. The patient was referred to our center with diagnosis of carotid cavernous fistula. The child had a history of episodes of seizures. RESULTS: Contrast-enhanced computed tomographic scan of the patient showed dilated vessels, hydrocephalus, and dilated vein of Galen. Vein of Galen aneurysmal malformation was confirmed on magnetic resonance venography. CONCLUSIONS: Occasionally patients with Vein of Galen aneurysmal malformation may first present to the ophthalmologist. Ophthalmologists should therefore be aware of this rare but potentially treatable condition.

Variable retinal presentations in nanophthalmos.

Nanophthalmos is an uncommon developmental ocular disorder characterized by a small eye with short axial length, high hyperopia and high lens/eye volume ratio due to arrested development of the globe in all directions. Different types of fundus changes can rarely occur with nanophthalmos. We describe five cases of nanophthalmos, each of them presenting with a different fundus appearance. Our case series highlights variability of pigmentary changes from retinal flecks to bone spicules and bull's eye maculopathy, which are rare in the combinations described here.

Ptosis associated with monocular elevation deficiency.

OBJECTIVE: To document the various clinical features of ptosis associated with monocular elevation deficiency (MED) seen in patients, presenting to the Paediatric and Strabismus Unit, over a period of 2 years. METHODS: All patients seen with monocular elevation deficiency presenting to the Strabismus Clinic from January 2006 to December 2007 were examined and evaluated for presence of associated ptosis, jaw winking phenomenon and pseudoptosis. Patients having acquired causes of monocular limitation in elevation were excluded. RESULTS: A total of 22 patients having MED were seen. Out of these 50% were males (N = 11) and 50% females (N = 11). Twelve (54.54%) had MED in the left eye and 10 (45.45%) had MED in the right eye. Ptosis was present in the eye affected with MED in 16 (72.72%) patients. Pseudoptosis was seen in 4 (18.18%) patients whereas no associated ptosis was noticed in 2 (9.09%) patients. Jaw winking phenomenon was present in 9 (40.90%) which comprise almost half (56%) the MED cases with ptosis. CONCLUSION: Careful clinical assessment for ptosis, pseudoptosis and jaw winking phenomenon before forced duction test, can help in planning the correct order of surgical management of patients having monocular elevation deficiency. The patient needs to be counseled regarding the multiple surgeries required according to associated clinical features present with MED.

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.

Detachment of Descemet's membrane following stromal hydration in phacoemulsification surgery.

Descemet's membrane detachment is mostly seen as a complication at the time of corneal incision. Stromal hydration for wound closure towards the end of phacoemulsification procedure is an unusual stage of surgery for this complication to occur. We report successful apposition of detached Descemet's membrane by using intracameral sulphur hexafluoride (SF6) gas in such a case.

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.

Ocular manifestations of xeroderma pigmentosum.

Xeroderma pigmentosum (XP) is an autosomal recessive (AR) condition characterized by photosensitivity and inability to repair ultra-violet (UV) induced DNA damage. Patients diagnosed with XP, presenting to the Paediatric ophthalmology department of Al-Shifa Trust Eye Hospital, Rawalpindi, were evaluated and followed-up over a period of one year, for the effects of the disease process on vision and for the development of ocular tumours. Excision of the tumours, if present, was performed under general anaesthesia. Counselling of the patients was done. Referral to oncologist and dermatologist was made, if so warranted, after histopathology of excision biopsy.

Retinoblastoma presenting as total hyphema: Three year follow-up.

Retinoblastoma very rarely presents as total hyphema. Our patient presented at an early age of 7 months. Follow-up of 3 years shows that unilateral group E retinoblastoma was treated successfully with enucleation and adjuvant chemotherapy. The fellow eye remained normal during this period. The factors associated with delay in treatment are also described. Reports like the present case add to the information available about advanced staging of retinoblastoma at the time of presentation, seen in cases with spontaneous hyphema due to the tumor.

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.

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.

Anisometropia and Ptosis in Patients with Monocular Elevation Deficiency.

OBJECTIVE: To determine the effect of ptosis on the refractive error in eyes having monocular elevation deficiency. STUDY DESIGN: Case series. PLACE AND DURATION OF STUDY: Al-Shifa Trust Eye Hospital, Rawalpindi, from January 2011 to January 2014. METHODOLOGY: Visual acuity, refraction, orthoptic assessment and ptosis evaluation of all patients having monocular elevation deficiency (MED) were recorded. Shapiro-Wilk test was used for tests of normality. Median and interquartile range (IQR) was calculated for the data. Non-parametric variables were compared, using the Wilcoxon signed ranks test. P-values of <0.05 were considered significant. RESULTS: Atotal of of 41 MED patients were assessed during the study period. Best corrected visual acuity (BCVA) and refractive error was compared between the eyes having MED and the unaffected eyes of the same patient. The refractive status of patients having ptosis with MED were also compared with those having MED without ptosis. Astigmatic correction and vision had significant difference between both the eyes of the patients. Vision was significantly different between the two eyes of patients in both the groups having either presence or absence of ptosis (p=0.04 and p < 0.001, respectively). CONCLUSION: Significant difference in vision and anisoastigmatism was noted between the two eyes of patients with MED in this study. The presence or absence of ptosis affected the vision but did not have a significant effect on the spherical equivalent (SE) and astigmatic correction between both the eyes.