Clinical and ocular abnormalities in DEGCAGS syndrome-Developmental delay with gastrointestinal, cardiovascular, genitourinary, and skeletal abnormalities.

PURPOSE: To describe clinical and ocular abnormalities in a case of Developmental Delay with Gastrointestinal, Cardiovascular, Genitourinary, and Skeletal Abnormalities (DEGCAGS syndrome). METHODS: A clinical report. CASE DESCRIPTION: An infant born to a consanguineous Middle Eastern family who was delivered by cesarean section because of in utero growth restriction, premature labor, and breech presentation. Post-partum medical problems included hypotension, generalized hypotonia, bradycardia, apnea requiring resuscitation and positive pressure ventilation, facial dysmorphia, skeletal malformations, and disorders of the gastrointestinal, immune, urinary, respiratory, cardiac, and visual systems. The family reported that a previous child had severe hypotonia at birth and was given the diagnosis of hypoxic ischemic encephalopathy; that child remains on a ventilator in a chronic care facility. Our patient was found to be homozygous for a novel pathogenic missense variant in theZNF699 zinc finger gene on chromosome 19p13 causing a syndrome known as Developmental Delay with Gastrointestinal, Cardiovascular, Genitourinary, and Skeletal Abnormalities (DEGCAGS syndrome). We review this variable syndrome, including abnormalities of the visual system not described previously. CONCLUSIONS: We describe the 15th child to be presumably identified with the DEGCAGS syndrome and the first individual with homozygous missense variants in the ZNF699 gene who had complete clinical examination and detailed retinal imaging.

Retinal Findings in Haemorrhagic Destruction of the Brain, Subependymal Calcification, and Congenital Cataracts (HDBSCC): Case Report and Review.

We describe a child from a consanguineous family born with a rare autosomal recessive disorder affecting junctional adhesion molecule 3 (JAM3) causing profound neurological and ophthalmological injury known as haemorrhagic brain destruction, subependymal calcifications, and congenital cataracts (HDBSCC; MIM# 613730). She was the product of an unremarkable pregnancy and was born near to term but was noted shortly after birth to have congenital cataracts, poor vision, increased muscle tone, seizures, and developmental delay. Her older sister had an identical syndrome and had previously been documented to have homozygous mutations in JAM3. Examination in our patient, although difficult because of bilateral central cataracts, revealed very poor vision, attenuated retinal vessels, optic atrophy, and a retinal haemorrhage in the right eye, implying that abnormal development of the retinas and/or optic nerves may at times play a significant role in the poor vision noted in children with HDBSCC.

Use of En Face Optical Coherence Tomography to Monitor Papilledema in Idiopathic Intracranial Hypertension: A Pilot Study.

BACKGROUND: En face optical coherence tomography (OCT) uses the data acquired during OCT of the optic disc, which typically is used to determine measurements of the peripapillary retinal nerve fiber layer (ppRNFL), to generate a coronal composite fundus image rather than a cross-sectional image. En face OCT has been reported to identify retinal changes related to papilledema in idiopathic intracranial hypertension (IIH) but has not been evaluated for monitoring papilledema. This study aimed to assess the reliability and validity of en face OCT for monitoring papilledema. METHODS: Using the Pearson correlation coefficient (R), these measurements were compared with ppRNFL thickness as well as average diameter and estimated area. Four fellowship-trained neuro-ophthalmologists were asked to qualitatively rank en face images by the area of optic disc edema while masked from all other clinical data. Rankings were compared with ppRNFL thickness as a gold standard and with en face OCT characteristics using the Pearson correlation coefficient (R). RESULTS: Experts were able to correctly identify an increase in average ppRNFL thickness >10 µm with a mean (SD) of 91% (±7%) accuracy. A ranking error among experts corresponded to a mean (standard error) change in the ppRNFL thickness of 6 (±6) µm. The mean Pearson correlation coefficient by the area of disc edema among experts was 0.92 (±0.13). CONCLUSIONS: Multiple objective parameters of en face OCT of optic disc edema have an excellent correlation with ppRNFL thickness. These results suggest that en face OCT is a valid clinical tool for monitoring papilledema in IIH.

NEW OBSERVATIONS REGARDING THE RETINOPATHY OF GENETICALLY CONFIRMED KEARNS-SAYRE SYNDROME.

PURPOSE: To report novel retinal findings in Kearns-Sayre syndrome and correlate degree of retinopathy with other clinical findings. METHODS: Observational case series of patients from Saudi Arabia with retinal and neuroophthalmologic examinations, medical chart review, and mitochondrial genetic evaluation. RESULTS: The three unrelated patients had progressive external ophthalmoplegia and pigmentary retinopathy bilaterally. Muscle biopsy in two of the cases revealed mitochondrial myopathy. All three had abnormal findings on neuroimaging and modestly reduced visual acuity in both eyes with a variable pigmentary retinopathy. One of the patients had bilateral subretinal fibrosis with a full-thickness macular hole in the right eye. All three patients had single, large-scale mitochondrial DNA (mtDNA) deletions (5.0-7.6 kb in size) with blood mtDNA heteroplasmy levels ranging from below 20% to 57%. Severity of pigmentary retinopathy did not correlate with severity of progressive external ophthalmoplegia, but did correspond grossly with electroretinographic abnormalities, just as the degree of ocular motility restriction and ptosis in each patient correlated with the size of their extraocular muscles on neuroimaging. In addition, the size of the single, large-scale mtDNA deletion and level of mtDNA heteroplasmy corresponded with degree of ocular motility restriction but not with severity of retinopathy. CONCLUSION: Subretinal fibrosis and macular hole are novel retinal observations which expand clinical profile in Kearns-Sayre syndrome. Genetic testing for mtDNA deletions and heteroplasmy in blood, muscle biopsy, careful ocular and retinal examination including electroretinography, and imaging are indispensable tests for this condition.

Biallelic mutations in human DCC cause developmental split-brain syndrome.

Motor, sensory, and integrative activities of the brain are coordinated by a series of midline-bridging neuronal commissures whose development is tightly regulated. Here we report a new human syndrome in which these commissures are widely disrupted, thus causing clinical manifestations of horizontal gaze palsy, scoliosis, and intellectual disability. Affected individuals were found to possess biallelic loss-of-function mutations in the gene encoding the axon-guidance receptor 'deleted in colorectal carcinoma' (DCC), which has been implicated in congenital mirror movements when it is mutated in the heterozygous state but whose biallelic loss-of-function human phenotype has not been reported. Structural MRI and diffusion tractography demonstrated broad disorganization of white-matter tracts throughout the human central nervous system (CNS), including loss of all commissural tracts at multiple levels of the neuraxis. Combined with data from animal models, these findings show that DCC is a master regulator of midline crossing and development of white-matter projections throughout the human CNS.

Clinicopathological features of peripheral nerve sheath tumors involving the eye and ocular adnexa.

Peripheral nerve sheath tumors (PNSTs) are known to occur in the orbit and comprise 4% of all orbital tumors, but have not been well studied in contemporary literature. Ninety specimens involving the eye and ocular adnexa (1979-2015) from 67 patients were studied. The mean age was 32.5years. Locations included orbit (58.9%), eyelid (60.0%), and other ocular adnexa. Most specimens were neurofibromas (70.0%), followed by schwannomas (11.1%), neuromas (11.1%), granular cell tumors (n=4), nerve sheath myxomas (n=2), and malignant PNST (n=1). Fifty-six (88.9%) neurofibroma cases were neurofibromatosis 1 associated. Among neurofibromas, 31.7% were localized, 38.1% were plexiform, 25.4% were diffuse, and 4.8% were diffuse and plexiform. These tumors involved skin (31.7%), soft tissue (11.1%), skeletal muscle (22.2%), peripheral nerve (63.0%), lacrimal gland (20.6%), and choroid (n=1). Other histologic findings included pseudo-Meissner corpuscles (27%), Schwann cell nodules (4.8%), prominent myxoid component (7.9%), melanin-like pigment (3.2%), and inflammation (14.3%). Available immunostains included S100 (+ in 15/15 cases), EMA (+ in 2/4 cases), CD34 (+ in 4/4 cases), and Ki-67 (<1% in 4/4 cases). Among 10 schwannomas, 8 were conventional and 2 were plexiform. Observed features included capsule (n=5), hyalinized vessels (n=5), Verocay bodies (n=7), and Antoni B pattern (n=5). Immunostaining included S100+ in 4 of 4 cases, and collagen IV+ and Ki-67 <1% in 3 of 3 cases. Neurofibromas are the most common PNST involving the eye and ocular adnexa, and the majority are associated with neurofibromatosis 1. Plexiform and diffuse patterns and the presence of pseudo-Meissner corpuscles are relatively frequent in this area.

Relative Frequencies of Arteritic and Nonarteritic Anterior Ischemic Optic Neuropathy in an Arab Population.

BACKGROUND: To evaluate the relative frequencies of arteritic and nonarteritic anterior ischemic optic neuropathy (AION) in an Arab population and to compare and contrast these findings with known epidemiological data from Caucasian populations. METHODS: A retrospective review of the medical records of all patients diagnosed with AION at the King Khaled Eye Specialist Hospital (KKESH) in Riyadh, Saudi Arabia, between 1997 and 2012. RESULTS: Of 171 patients with AION, 4 had biopsy-proven giant-cell arteritis (GCA). The relative frequencies of arteritic anterior ischemic optic neuropathy (AAION) and nonarteritic anterior ischemic optic neuropathy (NAION) in this Arab cohort were 2.3% and 97.7%, respectively. CONCLUSIONS: The relative frequencies of arteritic anterior ischemic optic neuropathy and nonarteritic anterior ischemic optic neuropathy differ between Arab and North American clinic-based populations, with giant-cell arteritis-related ischemia being much less frequent in Saudi Arabia.

Central Retinal Vein Occlusion in a Childhood Optic Nerve Tumour.

The authors describe the first paediatric patient with an aggressive optic nerve tumour of uncertain histology causing a central retinal vein occlusion, retinochoroidal collaterals, arteriovenous anastomoses, and peripheral retinal non-perfusion. He first presented with pale optic nerve head, followed by development of optic disc oedema a year later. Certain optic nerve tumours can present with central retinal vein occlusion in the paediatric age group.

The genetics of nonsyndromic bilateral Duane retraction syndrome.

PURPOSE: To assess the importance of monogenic mutations and chromosomal copy number variants (CNVs) in the occurrence of nonsyndromic bilateral Duane retraction syndrome (bilateral nsDRS). METHODS: The medical records of 12 patients with bilateral nsDRS were reviewed. Genes associated with DRS and associated congenital cranial dysinnervation disorders (SALL4, CHN1, HOXA1, TUBB3, and KIF21A) were sequenced in the standard fashion in each patient. Array comparative genomic hybridization (array CGH) was performed using Affymetrix Cytogenetics Whole-Genome 2.7M array, and the results were analyzed using Affymetrix Chromosome Analysis Suite v1.2. CNVs were assessed as unlikely to be pathologic if they were also present in the Database of Genomic Variants (DGV) or our local database of array CGH results in 150 normal individuals of Middle Eastern ethnicity. RESULTS: No patient had a sequence mutation in SALL4, CHN1, HOXA1, TUBB3, or KIF21A. These 12 patients each had 36-42 chromosomal deletions and/or duplications (mean with standard deviation, 26.25 ± 6.77), but all of these CNVs were present either in the DGV or in our local database of normal individuals of similar ethnicity and, therefore, are considered nonpathogenic. CONCLUSIONS: The results reported here suggest that bilateral nsDRS is not usually associated with mutations in these genes or with chromosomal CNVs. Current evidence suggests other factors such as epigenetic and/or teratogenic abnormalities may be a potential cause of bilateral nsDRS.

Coats-like retinopathy in Joubert syndrome.

An 11-year-old girl with Joubert syndrome was evaluated for a dim red reflex in her left eye. Fundus examination revealed retinal telangiectasias bilaterally compatible with Coats-like pigmentary retinopathy, a phenomenon not previously reported in Joubert syndrome. Coats-like exudative retinopathy may result in permanent visual loss if left untreated. The exudative retinopathy was controlled after multiple sessions of indirect laser photocoagulation and cryotherapy, with a good visual outcome.

Loss of MAFB Function in Humans and Mice Causes Duane Syndrome, Aberrant Extraocular Muscle Innervation, and Inner-Ear Defects.

Duane retraction syndrome (DRS) is a congenital eye-movement disorder defined by limited outward gaze and retraction of the eye on attempted inward gaze. Here, we report on three heterozygous loss-of-function MAFB mutations causing DRS and a dominant-negative MAFB mutation causing DRS and deafness. Using genotype-phenotype correlations in humans and Mafb-knockout mice, we propose a threshold model for variable loss of MAFB function. Postmortem studies of DRS have reported abducens nerve hypoplasia and aberrant innervation of the lateral rectus muscle by the oculomotor nerve. Our studies in mice now confirm this human DRS pathology. Moreover, we demonstrate that selectively disrupting abducens nerve development is sufficient to cause secondary innervation of the lateral rectus muscle by aberrant oculomotor nerve branches, which form at developmental decision regions close to target extraocular muscles. Thus, we present evidence that the primary cause of DRS is failure of the abducens nerve to fully innervate the lateral rectus muscle in early development.

Duane retraction syndrome in a patient with Duchenne muscular dystrophy.

PURPOSE: We describe the clinical features of a boy with bilateral Duane retraction syndrome (DRS), Duchenne muscular dystrophy (DMD), and other medical problems. METHODS: The child was followed-up for five years; his chart was reviewed, including the results of a muscle biopsy and genetic testing. Multiplex ligation-dependent probe amplification (MLPA) was used to interrogate deletions/duplications in the dystrophin gene. RESULTS: The proband had bilateral DRS with otherwise normal ocular motility; he also had developmental delay, mild mental retardation, and seizures. Clinical diagnosis of DMD included progressive proximal weakness, highly elevated creatine kinase levels, and a muscle biopsy showing significant dystrophic changes including contracted, degenerative, and regenerative fibers, and negative dystrophin immunostaining. MLPA documented duplication of exons 3 and 4 of the dystrophin gene. CONCLUSIONS: This boy is the third patient to be reported with DRS and DMD, the second with bilateral DRS and the only one with other neurologic features. Mutated dystrophin is present in extraocular muscles and in the central nervous system (CNS) in DMD, leaving open the question of whether this co-occurrence is the result of the genetic muscle abnormality, CNS effects caused by dystrophin mutations, or chance.

Retinal Dysfunction in Patients with Congenital Fibrosis of the Extraocular Muscles Type 2.

INTRODUCTION: Congenital fibrosis of the extraocular muscles type 2 (CFEOM2) is a distinct non-syndromic form of congenital incomitant strabismus secondary to orbital dysinnervation from recessive mutations in the gene PHOX2A. The phenotype includes bilateral ptosis, very large angle exotropia, ophthalmoplegia, and poorly-reactive pupils. Other than amblyopia, afferent visual dysfunction has not been considered part of CFEOM2; however, we have repeatedly observed non-amblyopic subnormal vision in affected patients. The purpose of this study was to document this recurrent feature of the phenotype. METHODS: A retrospective case series (2002-2012). RESULTS: Eighteen patients (four families) were identified; all affected individuals had confirmed homozygous recessive PHOX2A mutations except one individual for whom genetic testing was not done because of multiple genetically confirmed family members. Age at assessment ranged from 5-62 years old (median 10 years old). All patients had decreased best-corrected visual acuity not completely explainable by amblyopia in both the preferred and non-preferred eye. In those patients who had further ancillary testing, visual fields (five patients) and electroretinography (10 patients) confirmed abnormalities not ascribable to amblyopia. CONCLUSIONS: In addition to a distinct form of congenital incomitant strabismus, the phenotype of CFEOM2 includes subnormal vision consistent with retinal dysfunction. This could be the direct result of PHOX2A mutations or a secondary effect of orbital dysinnervation.

Mutation in GM2A Leads to a Progressive Chorea-dementia Syndrome.

BACKGROUND: The etiology of many cases of childhood-onset chorea remains undetermined, although advances in genomics are revealing both new disease-associated genes and variant phenotypes associated with known genes. METHODS: We report a Saudi family with a neurodegenerative course dominated by progressive chorea and dementia in whom we performed homozygosity mapping and whole exome sequencing. RESULTS: We identified a homozygous missense mutation in GM2A within a prominent block of homozygosity. This mutation is predicted to impair protein function. DISCUSSION: Although discovered more than two decades ago, to date, only five patients with this rare form of GM2 gangliosidosis have been reported. The phenotype of previously described GM2A patients has been typified by onset in infancy, profound hypotonia and impaired volitional movement, intractable seizures, hyperacusis, and a macular cherry red spot. Our findings expand the phenotypic spectrum of GM2A mutation-positive gangliosidosis to include generalized chorea without macular findings or hyperacusis and highlight how mutations in neurodegenerative disease genes may present in unexpected ways.

Visual and neurologic sequelae of methanol poisoning in Saudi Arabia.

OBJECTIVES: To present the visual sequelae of methanol poisoning and to emphasize the characteristics of methanol exposure in the Kingdom of Saudi Arabia (KSA). METHODS: A retrospective case series was carried out on 50 sequential patients with methanol poisoning seen at the King Khaled Eye Specialist Hospital and King Saud University Hospitals in Riyadh, KSA between 2008 and 2014. All patients were examined by a neuro-ophthalmologist at least one month after methanol intoxication. RESULTS: All 50 patients were young or middle-aged males. All admitted to drinking unbranded alcohol within 2-3 days before profound or relatively profound, painless, bilateral visual loss. Mean visual acuity in this group was hand motions (logMAR 2.82; range 0.1 - 5.0) with some eye to eye variability within individuals. Worse visual acuity was correlated with advancing age (Pearson correlation: oculus dextrus [right eye] - 0.37, p=0.008; oculus sinister [left eye] - 0.36, p=0.011). All patients had optic atrophy bilaterally, and all tested patients had visual field defects. Tremors with or without rigidity were present in 12 patients, and 11 of 30 patients who had neuroimaging performed had evidence of putaminal necrosis. CONCLUSION: Methanol intoxication causes visual loss within 12-48 hours due to relatively severe, painless, bilateral optic nerve damage that may be somewhat variable between eyes, and is generally worse with advancing age. The coincidence of bilateral optic nerve damage and bilateral putaminal necrosis in a young or middle-aged male is very suspicious for methanol-induced damage.

Cupping of the optic disk after methanol poisoning.

PURPOSE: To assess the frequency and significance of optic disk cupping after methanol poisoning. METHODS: We retrospectively reviewed the medical records of 50 consecutive patients with methanol poisoning, including visual acuity, pupillary reaction, and optic disk features such as the presence and degree of cupping. All patients were examined in the chronic phase after optic nerve damage. RESULTS: Optic disk cupping ≥0.8 c/d was present in at least one eye of 22 of these 50 patients (43/100 eyes). Severity of cupping was statistically symmetric in the two eyes, and increasing severity of cupping was correlated with worse visual acuity (p=0.007) and increasing visual field loss. Degree of cupping was significantly correlated with increasing patient age but not with putaminal necrosis. CONCLUSIONS: Optic disk cupping after methanol poisoning may be more common than previously recognised. Cupping in this setting may reflect toxicity of methanol metabolites to axons and glial cells in the prelaminar, laminar and retrolaminar regions, and seems to be important as a marker for worse optic nerve damage.

CCDD Phenotype Associated with a Small Chromosome 2 Deletion.

PURPOSE: Some individuals are born with congenital limitation of ocular motility, often associated with ptosis and retraction of the globe. Many of these disorders are now known as the congenital cranial dysinnervation disorders (CCDDs). While several genes have been associated with CCDD phenotypes, there are still patients for whom the genetic basis has not been identified. METHODS: Clinical evaluation and neuroimaging, sequencing of candidate genes, and array comparative genomic hybridization (array CGH). RESULTS: The patient was a four-year-old girl with mild dysmorphism; bilateral mild ptosis; substantial limitation of abduction OS with milder limitations of abduction OD, adduction OS, and vertical gaze OS; and retraction OS > OD on attempted adduction. No mutations were detected in the HOXA1, KIF21A, SALL4, TUBB3, and CHN1 genes. Array CGH revealed a 8 Kb de novo deletion on chromosome 2 (2q24.3) that encompassed a portion of only one gene, the Xin Actin-binding Repeat containing 2 (Gene Symbol XIRP2; NM_001079810). This gene encodes a protein that is involved in muscle development and protecting actin filaments from depolymerization. It interacts functionally with 10 other proteins playing a similar role in muscle development. CONCLUSIONS: This patient's chromosomal abnormality affected only one gene that currently seems involved only in muscle development. All other genes currently associated with the CCDDs affect neurologic development. Genetic information from this patient implies that genes involved in development and maintenance of extraocular muscles can cause congenital ocular motility disorders as well.