The eye in the CHARGE association

Ocular manifestations of CHARGE syndrome in a pediatric cohort with genotype/phenotype analysis

CHARGE syndrome is a rare multi-system condition associated with CHD7 variants. However, ocular manifestations and particularly ophthalmic genotype-phenotype associations, are not well-studied. This study evaluated ocular manifestations and genotype-phenotype associations in pediatric patients with CHARGE syndrome. A retrospective chart review included pediatric patients under 20 years-old with clinical diagnosis of CHARGE syndrome and documented ophthalmic examination. Demographics, genetic testing, and ocular findings were collected. Comprehensive literature review enhanced the genotype-phenotype analysis. Forty-two patients (20 male) underwent eye examination at an average age of 9.45 ± 6.52 years-old. Thirty-nine (93%) had ophthalmic manifestations in at least one eye. Optic nerve/chorioretinal colobomas were most common (38 patients), followed by microphthalmia (13), cataract (6), and iris colobomas (4). Extraocular findings included strabismus (32 patients), nasolacrimal duct obstructions (11, 5 with punctal agenesis), and cranial nerve VII palsy (10). Genotype-phenotype analyses (27 patients) showed variability in ocular phenotypes without association to location or variant types. Splicing (10 patients) and frameshift (10) variants were most prevalent. Patients with CHARGE syndrome may present with a myriad of ophthalmic manifestations. There is limited data regarding genotype-phenotype correlations and additional studies are needed.

Ocular manifestations of congenital anomalies of the kidney and urinary tract (CAKUT)

Congenital anomalies of the kidney and urinary tract (CAKUT) are among the most common birth defects worldwide and a major cause of kidney failure in children. Extra-renal manifestations are also common. This study reviewed diseases associated with the Genomics England CAKUT-associated gene panel for ocular anomalies. In addition, each gene was examined for expression in the human retina and an ocular phenotype in mouse models using the Human Protein Atlas and Mouse Genome Informatics databases, respectively. Thirty-four (54%) of the 63 CAKUT-associated genes (55 'green' and 8 'amber') had a reported ocular phenotype. Five of the 6 most common CAKUT-associated genes (PAX2, EYA1, SALL1, GATA3, PBX1) that represent 30% of all diagnoses had ocular features. The ocular abnormalities found with most CAKUT-associated genes and with five of the six commonest were coloboma, microphthalmia, optic disc anomalies, refraction errors (astigmatism, myopia, and hypermetropia), and cataract. Seven of the CAKUT-associated genes studied (11%) had no reported ocular features but were expressed in the human retina or had an ocular phenotype in a mouse model, which suggested further possibly-unrecognised abnormalities. About one third of CAKUT-associated genes (18, 29%) had no ocular associations and were not expressed in the retina, and the corresponding mouse models had no ocular phenotype. Ocular abnormalities in individuals with CAKUT suggest a genetic basis for the disease and sometimes indicate the affected gene. Individuals with CAKUT often have ocular abnormalities and may require an ophthalmic review, monitoring, and treatment to preserve vision.

Inherited causes of combined vision and hearing loss: clinical features and molecular genetics

Combined vision and hearing loss, also known as dual sensory impairment, can occur in several genetic conditions, including ciliopathies such as Usher and Bardet-Biedl syndrome, mitochondrial DNA disorders and systemic diseases, such as CHARGE, Stickler, Waardenburg, Alport and Alstrom syndrome. The retinal phenotype may point to the diagnosis of such disorders. Herein, we aim to provide a comprehensive review of the molecular genetics and clinical features of the most common non-chromosomal inherited disorders to cause dual sensory impairment.

Pervasive cortical and white matter anomalies in a mouse model for CHARGE syndrome

CHARGE (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth, Genital anomalies and Ear abnormalities) syndrome is a disorder caused by mutations in the gene encoding CHD7, an ATP dependent chromatin remodelling factor, and is characterised by a diverse array of congenital anomalies. These include a range of neuroanatomical comorbidities which likely underlie the varied neurodevelopmental disorders associated with CHARGE syndrome, which include intellectual disability, motor coordination deficits, executive dysfunction, and autism spectrum disorder. Cranial imaging studies are challenging in CHARGE syndrome patients, but high-throughput magnetic resonance imaging (MRI) techniques in mouse models allow for the unbiased identification of neuroanatomical defects. Here, we present a comprehensive neuroanatomical survey of a Chd7 haploinsufficient mouse model of CHARGE syndrome. Our study uncovered widespread brain hypoplasia and reductions in white matter volume across the brain. The severity of hypoplasia appeared more pronounced in posterior areas of the neocortex compared to anterior regions. We also perform the first assessment of white matter tract integrity in this model through diffusion tensor imaging (DTI) to assess the potential functional consequences of widespread reductions in myelin, which suggested the presence of white matter integrity defects. To determine if white matter alterations correspond to cellular changes, we quantified oligodendrocyte lineage cells in the postnatal corpus callosum, uncovering reduced numbers of mature oligodendrocytes. Together, these results present a range of promising avenues of focus for future cranial imaging studies in CHARGE syndrome patients.

Insights Regarding Optometric Findings of CHARGE Syndrome in a Pediatric Low Vision Clinic

SIGNIFICANCE

CHARGE, named for common findings-coloboma, heart defects, atresia of choanae, retardation of growth and development, genital hypoplasia, and ear anomalies-is a frequent etiology of deaf-blindness. A retrospective review in a pediatric low vision clinic presented the opportunity to investigate ocular findings in this syndrome with variable clinical presentations.

PURPOSE

This retrospective study reviewed ocular findings and visual function measures from low vision evaluations of patients with CHARGE syndrome, which may influence their multidisciplinary management.

METHODS

A retrospective chart review was conducted by three examiners of 60 patients presenting with CHARGE syndrome at a pediatric low vision clinic. Visual acuity and contrast sensitivity were obtained using standard measures. Ocular alignment and cycloplegic refractive error measurements were recorded. Refractive findings were analyzed using vector analysis. Anterior and posterior segment findings were recorded.

RESULTS

Patients ranged in age from 1 to 29 years and were followed up for a mean of 4.3 years. Best-corrected visual acuity ranged from no light perception to 20/20 Snellen equivalent. Characteristics of strabismus, occurring in 82% of patients, were reported. Contrast sensitivity was reduced in 52% of patients. Chorioretinal colobomas were reported in 88% of patients. The most common ocular findings included nystagmus (43%), microphthalmia (27%), iris coloboma (27%), and facial nerve palsy (23%). Refractive vector analysis revealed significant myopic progression of the spherical equivalent with age and a tendency for with-the-rule astigmatism and minimal obliquity.

CONCLUSIONS

This retrospective review of a relatively large sample size for this rare condition outlined the most common ocular manifestations of CHARGE syndrome. Decreased visual acuity, myopic refractive error, strabismus, and reduced contrast sensitivity were common. Thus, careful optometric evaluation in this population is required, as these findings must be considered in appropriate clinical and habilitative management.

Chromatin remodeler Chd7 regulates photoreceptor development and outer segment length

Mutations in the chromatin remodeling factor CHD7 are the predominant cause of CHARGE syndrome, a congenital disorder that frequently includes ocular coloboma. Although CHD7 is known to be required for proper ocular morphogenesis, its role in retinal development has not been thoroughly investigated. Given that individuals with CHARGE syndrome can experience visual impairment even in the absence of coloboma, a better understanding of CHD7 function in the retina is needed. In this study, we characterized the expression pattern of Chd7 in the developing zebrafish and mouse retina and documented ocular and retinal phenotypes in Chd7 loss-of-function mutants. Zebrafish Chd7 was expressed throughout the retinal neuroepithelium when retinal progenitor cells were actively proliferating, and later in subsets of newly post-mitotic retinal cells. At stages of retinal development when most retinal cell types had terminally differentiated, Chd7 expression remained strong in the ganglion cell layer and in some cells in the inner nuclear layer. Intriguingly, strong expression of Chd7 was also observed in the outer nuclear layer where it was co-expressed with markers of post-mitotic cone and rod photoreceptors. Expression of mouse CHD7 displayed a similar pattern, including expression in the ganglion cells, subsets of inner nuclear layer cells, and in the distal outer nuclear layer as late as P15. Two different mutant chd7 zebrafish lines were characterized for ocular and retinal defects. These mutants displayed microphthalmia, reduced numbers of cone photoreceptors, and truncated rod and cone photoreceptor outer segments. Reduced cone photoreceptor number and abnormal outer segments were also observed in heterozygous Chd7 mutant mice. Taken together, our results in zebrafish and mouse reveal a conserved, previously undescribed role for Chd7 in retinal development and photoreceptor outer segment morphogenesis. Moreover, our work suggests an avenue of future investigation into the pathogenesis of visual system defects in CHARGE syndrome.

Eyes on CHARGE syndrome: Roles of CHD7 in ocular development

The development of the vertebrate visual system involves complex morphogenetic interactions of cells derived from multiple embryonic lineages. Disruptions in this process are associated with structural birth defects such as microphthalmia, anophthalmia, and coloboma (collectively referred to as MAC), and inherited retinal degenerative diseases such as retinitis pigmentosa and allied dystrophies. MAC and retinal degeneration are also observed in systemic congenital malformation syndromes. One important example is CHARGE syndrome, a genetic disorder characterized by coloboma, heart defects, choanal atresia, growth retardation, genital abnormalities, and ear abnormalities. Mutations in the gene encoding Chromodomain helicase DNA binding protein 7 (CHD7) cause the majority of CHARGE syndrome cases. However, the pathogenetic mechanisms that connect loss of CHD7 to the ocular complications observed in CHARGE syndrome have not been identified. In this review, we provide a general overview of ocular development and congenital disorders affecting the eye. This is followed by a comprehensive description of CHARGE syndrome, including discussion of the spectrum of ocular defects that have been described in this disorder. In addition, we discuss the current knowledge of CHD7 function and focus on its contributions to the development of ocular structures. Finally, we discuss outstanding gaps in our knowledge of the role of CHD7 in eye formation, and propose avenues of investigation to further our understanding of how CHD7 activity regulates ocular and retinal development.

Ocular Coloboma With Choroidal Neovascular Membrane: A Case Report

Ocular coloboma (OC) is a rare congenital anomaly and a product of a defect in embryogenesis. It is the result of fetal fissure closure error that ends with a persistent cleft. Colobomas are generally accompanied by visual loss. In this article, we present a case of bilateral iris, disc, and retina coloboma that was managed with an anti-vascular endothelial growth factor (ranibizumab), and as a result, caused regression of the choroidal neovascular membranes and improved the patient's visual acuity. However, The patient will need lifelong follow-up to catch any retinochoroidal changes or development of cataract or glaucoma.

CHARGE Syndrome Associated with Ocular Abnormalities: A Case Report with Treatment of Amblyopia and Refractive Correction

CHARGE syndrome is a rare genetic disorder associated with many ocular anomalies including amblyopia, strabismus and high refractive errors. It has been found that the visual acuity of patients with CHARGE syndrome is typically lower than 20/60. After reviewing the literature, there has been a lack of detailed information about the assessments of visual function. Thus, this case report illustrates the strategy plan to treat amblyopia and refractive correction for a young girl with CHARGE syndrome.

Visual Function and Ophthalmological Findings in CHARGE Syndrome: Revision of Literature, Definition of a New Clinical Spectrum and Genotype Phenotype Correlation

CHARGE syndrome (CS) is a rare genetic disease causing multiple anatomical defects and sensory impairment. Visual function is usually reported by caregivers and has never been described with a structured behavioral assessment. Our primary objective was to describe ocular abnormalities, visual function and genotype–ocular-phenotype correlation in CS. A prospective monocentric cohort study was performed on 14 children with CS carrying pathogenic CHD7 variants. All children underwent ophthalmological evaluation and structured behavioral assessment of visual function. The VISIOCHARGE questionnaire was administered to parents. Colobomas were present in 93% of patients. Genotype–phenotype correlation documented mitigated features in a subset of patients with intronic pathogenic variants predicted to affect transcript processing, and severe features in patients with frameshift/nonsense variants predicting protein truncation at the N-terminus. Abnormal visual function was present in all subjects, with different degrees of impairment. A significant correlation was found between visual function and age at assessment (p-value = 0.025). The present data are the first to characterize visual function in CS patients. They suggest that hypomorphic variants might be associated with milder features, and that visual function appears to be related to age. While studies with larger cohorts are required for confirmation, our data indicate that experience appears to influence everyday use of visual function more than ocular abnormalities do.

Punctal agenesis and delayed-onset dacryocystocele in CHARGE syndrome

Punctal agenesis and other nasolacrimal abnormalities have been infrequently reported in CHARGE syndrome-a constellation of findings affecting the eyes, heart, choana, and ears-which generally presents at birth. We present a rare case of punctal agenesis with delayed-onset dacryocystocele/lacrimal sac mucocele in a teenager with CHARGE syndrome.

Clinical and histological features and outcomes of upper eyelid colobomas in the Saudi population

PURPOSE

To study the clinical features, histopathology, and management of congenital upper eyelid coloboma (CEC) in the Saudi population.

METHODS

A retrospective review of health records evaluated the demographics, histopathology, and surgical outcomes of patients with CEC.

RESULTS

Thirty-nine eyelids of 27 patients were included in this study. CEC was bilateral in 12 (44.4%) patients, isolated in 17 (62.9%), and as part of a syndrome in 10 (37.1%) patients. CEC was commonly located in the medial upper lid (22 lids, 56.4%) and mostly involved the full thickness of the lid (27 lids, 69.2%). Corneal adhesion (18 eyes, 46.1%) and poorly formed eyebrows (21 eyebrows, 53.8%) were the most common ocular/adnexa associations. Histopathology was similar in all cases and the main features were scarred dermis, atrophic orbicularis oculi, and atrophic or absent tarsus. Visual acuity at the final follow-up was 20/50 or better in 13 (33.3%) eyes. Complete lid closure without lagophthalmos after one or more surgical procedures was achieved in 11 (40.7%) cases.

CONCLUSIONS

CEC features in Saudi patients are similar to those described in the literature. Dermal scarring and defective orbicularis muscles are common. Achieving cosmetic and functional success after management remains challenging.

CHARGE syndrome without colobomas: Ophthalmic findings

To report ophthalmic findings of patients without colobomas, and with a clinical and molecular diagnosis of CHARGE Syndrome. Retrospective study of ophthalmic findings in 67 CHARGE patients-clinically confirmed diagnosis with positive CHD7 mutation-seen in the Ophthalmology department of Cincinnati Children's Hospital Medical Center between January 1, 2008 through September 25, 2018. Criteria for inclusion in this study was absence of any form of a coloboma in either eye. In our cohort, all patients had a positive CHD7 mutation, in addition to a clinical diagnosis. 19.4% (13/67) of CHARGE patients did not have a coloboma in either eye. 69.2% (9/13) had strabismus, 76.9% (10/13) had a refractive error that warranted refractive correction, 23.1% (3/13) had amblyopia, 38.5% (5/13) had nasolacrimal duct obstruction, 30.8% (4/13) had dry eye syndrome and exposure keratopathy, 15.4% (2/13) had ptosis, 15.4% (2/13) had blepharitis, 15.4% (2/13) had Cortical Visual Impairment, 7.7% (1/13) of patients had optic nerve drusen, 7.7% (1/13) had Marcus Gunn Jaw Winking, and 7.7% (1/13) with an eyelid nevus. There are numerous ophthalmic findings in individuals with CHARGE Syndrome without colobomas. No study to date has evaluated the ophthalmic findings in CHD7 positive CHARGE patients without colobomas. These findings need to be assessed and treated to ensure optimal vision in the CHARGE patient population. Absence of coloboma does not rule out a diagnosis of CHARGE syndrome, and if there is a clinical suspicion, clinical confirmation then genetic testing would be warranted.

Functional Vision Analysis in Patients With CHARGE Syndrome

PURPOSE

To evaluate functional vision in patients with CHARGE syndrome (coloboma, heart defects, atresia of the choanae, retardation of growth and development, genital and urinary anomalies, and ear anomalies) by using a new questionnaire entitled VISIOCHARGE.

METHODS

Ophthalmological data including fundus description and visual acuity, when available, were extracted from the charts of 83 patients with CHARGE syndrome, and the VISIOCHARGE questionnaire was prospectively mailed to 55 of those patients. The answers from the 36 responders (18 males) allowed for the calculation of three scores that assessed distance vision, near vision, and overall ability scores.

RESULTS

Visual acuity measurements were extracted from the charts of 20 of the 36 patients. The mean visual acuity was 20/50. The mean distance vision score of 0.62 ± 0.30 and near vision score of 0.78 ± 0.23 were correlated with visual acuity in the 20 patients (ρ = 0.64, P = .002 and ρ = 0.61, P = .005, respectively) and were associated with the severity of colobomatous malformation (P = .049 and P = .008, respectively). Severity of the ocular malformation was not associated with the overall ability score (P = .64).

CONCLUSIONS

The VISIOCHARGE questionnaire is feasible for patients with CHARGE syndrome and may help in the assessment of visual function. The mean visual acuity and answers to the VISIOCHARGE questionnaire showed relatively good visual skills in patients with CHARGE syndrome in everyday life, even in those with bilateral colobomas, which contrasts with the pessimistic conclusions usually resulting from the initial fundus examination. [J Pediatr Ophthalmol Strabismus. 2020;57(2):120-128.].

CHARGE Syndrome Associated with Angle Closure despite High Myopia: A Case Report with Structural Suggestion

CHARGE syndrome is associated with multiple malformations, and the main ocular abnormality is coloboma. We describe an unusual case of a 15-year-old girl with CHARGE syndrome having high intraocular pressure and narrow angle closure despite refractive high myopia (−9.0 dpt) in her left eye. Gonioscopy revealed peripheral anterior synechia (approximately 90°) in the superior quadrant of the left eye. Both eyes exhibited similar axial length (about 22 mm) and corneal curvature (about 8 mm). However, microcornea (9 mm), thicker central cornea and iris induced narrower anterior components in the left eye than in the right eye. Preventing the chance of acute primary angle closure attack, the patient underwent laser iridotomy in the left eye; however, long-term follow-up is needed. Additionally, we developed a hypothesis for the mechanism of unilateral angle closure despite high myopia by investigating the ocular structural parameters in detail.

Lacrimal Drainage Anomalies in CHARGE Syndrome: Case Report and Review of Literature

The common ocular manifestations of CHARGE syndrome include colobomatous defects in the eye, strabismus, nystagmus, and micropthalmia. Lacrimal drainage anomalies have been rarely reported and to the best of the authors' knowledge, only 5 such cases have been reported earlier. The present case describes CHARGE syndrome associated with bilateral complex congenital nasolacrimal duct obstruction with multiple prior attacks of acute dacryocystitis and left lower punctal agenesis, successfully managed with a right-sided dacryocystorhinostomy and awaiting a left dacryocystorhinostomy.Lacrimal drainage anomalies in CHARGE syndrome include complex CNLDO, punctal agenesis, and acute dacryocystitis.

Optic Nerve Hypoplasia and Crouzon Syndrome

Crouzon syndrome is the most common cause of syndromic craniosynostosis. The authors present a previously unreported association between Crouzon syndrome and optic nerve hypoplasia. A male infant was transferred to the center for treatment of respiratory distress. He was diagnosed as having dysmorphic features, a membranous choanal stenossi bilaterally, and bilateral optic nerve hypoplasia. Genetic testing confirmed a molecular diagnosis of Crouzon syndrome. He had a complicated course in relation to choanal stenosis management, and was discharged home at 10 weeks of age. Although uncommon in Crouzon syndrome, the association with optic nerve hypoplasia changes the initial work-up and the management of parental expectations. [J Pediatr Ophthalmol Strabismus. 2018;55:e45-e48.].

Guidelines in CHARGE syndrome and the missing link: Cranial imaging

"CHARGE syndrome" is a complex syndrome with high and extremely variable comorbidity. As a result, clinicians may struggle to provide accurate and comprehensive care, and this has led to the publication of several clinical surveillance guidelines and recommendations for CHARGE syndrome, based on both single case observations and cohort studies. Here we perform a structured literature review to examine all the existing advice. Our findings provide additional support for the validity of the recently published Trider checklist. We also identified a gap in literature when reviewing all guidelines and recommendations, and we propose a guideline for neuroradiological evaluation of patients with CHARGE syndrome. This is of importance, as patients with CHARGE are at risk for peri-anesthetic complications, making recurrent imaging procedures under anesthesia a particular risk in clinical practice. However, comprehensive cranial imaging is also of tremendous value for timely diagnosis, proper treatment of symptoms and for further research into CHARGE syndrome. We hope the guideline for neuroradiological evaluation will help clinicians provide efficient and comprehensive care for individuals with CHARGE syndrome.

Syndromic and Nonsyndromic Systemic Associations of Congenital Lacrimal Drainage Anomalies: A Major Review

PURPOSE

To review and summarize the syndromic, nonsyndromic, and systemic associations of congenital lacrimal drainage anomalies.

METHODS

The authors performed a PubMed search of all articles published in English on congenital lacrimal anomalies (1933-2016). Patients of these articles were reviewed along with the literature of direct references to syndromes and other systemic associations. Data reviewed included syndromic descriptions, systemic details, demographics, lacrimal presentations, management, and outcomes.

RESULTS

Syndromic and systemic associations with congenital lacrimal drainage disorders are not known to be common. Although familial presentations have been reported, the inheritance patterns are unclear for most anomalies. There is an increasingly growing evidence of a genetic basis to many lacrimal anomalies. However, few syndromes have either widespread or are frequently associated with lacrimal anomalies. Few sequences of distinct lacrimal presentations and intraoperative findings are seen. Surgical challenges in these patients are distinct and a thorough pre and intraoperative anatomical assessment, detailed imaging when indicated, and assessment and correction of associated periocular and facial abnormalities may facilitate good outcomes.

CONCLUSIONS

Lacrimal drainage anomalies associated with syndromic and nonsyndromic systemic conditions have certain unique features of their own and their surgical and anesthesia challenges are distinct. Diagnosis of congenital lacrimal drainage anomalies should prompt consideration of the possible presence of associated systemic abnormalities.

Congenital Glaucoma and CHARGE Syndrome: A Case Report

PURPOSE

To report a rare case of congenital glaucoma in a patient with CHARGE syndrome, present gonioscopic photographs, and explore mechanisms of disease that may account for this association.

PATIENTS AND METHODS

We describe a 35-week-old girl with previously diagnosed CHARGE syndrome who presented with corneal edema, buphthalmos, and elevated intraocular pressure in the left eye. She was subsequently diagnosed with congenital glaucoma and started on topical and oral therapy.

RESULTS

Examination under anesthesia confirmed the above findings as well as bilateral abnormal angles with an anterior iris insertion at the level of the posterior trabecular meshwork, prominent iris vasculature and stromal strands, and nonvisible scleral spur and ciliary body bands. Trabeculotomy and trabeculectomy were performed in the left eye with a poor outcome. CHARGE syndrome is a complex neurocristopathy, and we propose that the abnormal angle findings and associated asymmetric glaucoma in our patient share a common mechanism of neural crest cell dysfunction.

CONCLUSIONS

CHARGE syndrome can be associated with congenital glaucoma and we emphasize the importance of a thorough ophthalmic examination to detect glaucoma with surgical management as deemed appropriate.

Cochlear Implantation in Patients With CHARGE Syndrome

OBJECTIVE

To determine the optimal surgical approach for cochlear implantation (CI) preoperatively based on the spatial relation of a displaced facial nerve (FN) and middle ear structures and to analyze clinical outcomes of CHARGE syndrome.

METHODS

Facial nerve displacement and associated deviation of inner ear structures were analyzed in 13 patients (17 ears) with CHARGE syndrome who underwent CI. Surgical accessibility through the facial recess was assessed based on anatomical landmarks. Postoperative speech performance and associated clinical characteristics were analyzed.

RESULTS

The most consistently identified ear anomalies were semicircular canal aplasia (100%), ossicular anomaly (100%), and vestibular hypoplasia (88%). Facial nerve displacement was found in 77% of cases (anteroinferior: 47%, anterior: 24%, inferior: 6%). The width of available surgical space around facial recess was significantly greater in cases of facial recess approach (2.85 ± 0.9 mm) than those of alternative approach (0.12 ± 0.29 mm, P = .02). Postoperatively, 53% achieved better than category 4 on the categories of auditory perception (CAP) scale. The CAP category was significantly correlated with internal auditory canal diameter (P = .025) and did not differ according to the applied surgical approach.

CONCLUSION

Preoperative determination of surgical accessibility through facial recess would be useful for safe surgical approach, and successful hearing rehabilitation was achievable by applying appropriate surgical approaches.

CHARGE syndrome: a review

CHARGE syndrome is a complex genetic syndrome, owing to the wide range of tissues/systems affected by mutations in the CHD7 gene. In this review, we discuss the diagnosis, clinical features and management of CHARGE syndrome.

Two cases of CHARGE syndrome with multiple congenital anomalies

We report on two cases of bilateral chorioretinal colobomas with ocular anomalies in patients with CHARGE syndrome. In the first case, a female infant was born at 36 + 5 weeks gestation. At birth, the patient demonstrated a small left eye. Slit-lamp examination revealed colobomas of both irises. Fundus examination showed both chorioretinal colobomas. Brain magnetic resonance imaging (MRI) showed left microphthalmia. Systemic evaluation revealed multiple congenital anomalies: benign external hydrocephalus, esophageal atresia with imperforate anus, atrial septal defect (ASD), ventricular septal defect, patent ductus arteriosis (PDA), and right mild hydronephrosis. In the second case, a male infant was born at 39 + 5 weeks gestation and demonstrated a dysmorphic appearance with an irregular left pupil and ptosis. Fundus examination of both eyes showed large chorioretinal colobomas involving the optic disc and posterior pole. The patient had multi-organ anomalies: right facial palsy, a left short, wide ear with a small lobe, congenital heart defects, such as ASD and PDA, left renal atresia, seizure disorder, and micropenis. Both cases revealed multiple anomalies including nearly all major and minor criteria of CHARGE syndrome which could be life-threatening to neonates. Thus, all neonates with ocular colobomas should have fully and detailed systemic examinations checking all minor criteria and even occasional findings of CHARGE syndrome.

Ophthalmic features of CHARGE syndrome with CHD7 mutations

Coloboma and various ocular abnormalities have been described in CHARGE syndrome, although the severity of visual impairment varies from case to case. We conducted a multicenter study to clarify the ophthalmic features of patients with molecularly confirmed CHARGE syndrome. Thirty-eight eyes in 19 patients with CHARGE syndrome and confirmed CHD7 mutations treated at four centers were retrospectively studied. Colobomata affected the posterior segment of 35 eyes in 18 patients. Both retinochoroidal and optic disk colobomata were bilaterally observed in 15 patients and unilaterally observed in 3 patients. The coloboma involved the macula totally or partially in 21 eyes of 13 patients. We confirmed that bilateral large retinochoroidal colobomata represents a typical ophthalmic feature of CHARGE syndrome in patients with confirmed CHD7 mutations; however, even eyes with large colobomata can form maculas. The anatomical severity of the eye defect was graded according to the presence of colobomata, macula defect, and microphthalmos. A comparison of the severity in one eye with that in the other eye revealed a low-to-moderate degree of agreement between the two eyes, reflecting the general facial asymmetry of patients with CHARGE syndrome. The location of protein truncation and the anatomical severity of the eyes were significantly correlated. We suggested that the early diagnosis of retinal morphology and function may be beneficial to patients, since such attention may determine whether treatment for amblyopia, such as optical correction and patching, will be effective in facilitating the visual potential or whether care for poor vision will be needed.

Visual electrophysiological findings in CHARGE syndrome with bilateral colobomas: a case report

Colobomas are the major ophthalmic manifestation of CHARGE syndrome. Ophthalmological advice may be sought for an infant diagnosed with CHARGE syndrome presenting with coloboma, and electrophysiology can be particularly useful in assessing retinal and cortical function at an early age. Here we describe electrophysiology findings in a four-week-old infant born with bilateral coloboma, more extensive in the right eye, as part of CHARGE syndrome. The left eye showed robust ERGs indicating near-normal rod and cone function. The right eye ERG amplitudes were relatively reduced being around one half to two-thirds that of the left eye ERGs. Flash VEPs were present from both left and right eyes, but the right eye VEP was smaller and delayed relative to that of the left eye. By 5 years of age, right eye acuity was approximately 6/1000 and left eye acuity was 6/12 (Cardiff cards). In cases such as this, it is helpful to give parents a reasonable prediction of visual outcome as soon as possible, allowing instigation of appropriate management and permitting parents to begin to come to terms with the diagnosis. Electrophysiology can provide valuable information on visual function when behavioural testing is limited by the child's ability to co-operate, such as during the early weeks of life.

CHARGE syndrome: relations between behavioral characteristics and medical conditions

The behaviors and medical problems in 27 persons with CHARGE syndrome were studied, because it was hypothesized that their behavior might be partly dependent on the heterogeneous medical status. With the exception of more tics, cardiac surgery was associated with positive behaviors: less withdrawn behavior, better mood, and a more easy temperament. Tube feeding was also related to positive behavior, since participants with a history of tube feeding showed less intense behavior. Cerebral deficits were associated with three problem behaviors: more intense and withdrawn behavior and a worse mood. Deaf-blindness was associated with developmental delays in expressive and overall communication level, and recurrent middle ear infections correlated with delays in written language. Of all medical conditions, only the presence or absence of heart defects and cardiac surgery could differentiate between the participants with regard to the number of behavioral problems. Participants with heart surgery especially, had less behavior problems. The number of operations and hospitalizations was not associated with behavior, but the total length of the hospitalizations was. Long hospital stays were associated with less problem behavior, especially internalizing behaviors. Cerebral and heart problems did not result in longer hospital stays, whereas esophageal reflux did. Age effects were reflected in older participants, who showed more internalizing problems. Heart surgery and hospitalization may be protective factors, but the protection might not be the actual surgery or hospital stay, as there may be other variables that are the actual cause, such as reduced vitality or altered parent child interactions after heart surgery. The study could not confirm a significant association between medical conditions and autism found in previous studies.

Ocular features of CHARGE syndrome

PURPOSE

To detail the presence and severity of ocular and cranial nerve abnormalities found in individuals with CHARGE syndrome in a distinct geographic area.

METHODS

Nine individuals with CHARGE syndrome from Maritime Canada identified from a Canadian database were prospectively examined. Structural and sensorial defects associated with functional visual deficits were defined with ophthalmic and neurological evaluation.

RESULTS

Consistent with current diagnostic criteria and the literature, colobomas were the major ophthalmic manifestation. These were typically bilateral chorioretinal colobomas involving the optic nerve. All subjects had bilateral severe sensorineural deafness (cranial nerve VIII), and 8 of 9 (89%) had facial nerve (cranial nerve VII) involvement (7 of 9 had unilateral involvement; 1 of 9 had bilateral involvement). Unique to this group of participants were the findings of anisometropia in 8 of the 9 (89%) patients, severe myopic astigmatism in 13 of the 18 eyes (72%), and limited elevation in adduction in 3 of 9 (33%) participants. Associated findings were strabismus, cataracts, microcornea, keratopathy, staphyloma, reduced stereopsis, superior visual field defects, and reduced visual acuity.

CONCLUSIONS

The presence of coloboma plus another CHARGE feature warrants further investigation, including genetic screening for the CHD7 gene. Early recognition and management of sensory problems (visual, auditory, and vestibular) are crucial to ensure best psychomotor and cognitive development.

Update on the morning glory disc anomaly

The morning glory disc anomaly has distinctive clinical characteristics and is important to diagnose correctly so that associated central nervous system and vascular abnormalities are promptly identified and treated. This review covers the ophthalmic findings, clinical features, and histopathologic findings in patients with this rare developmental abnormality. The most common systemic associations are described and reviewed.

Congenital diaphragmatic hernia in CHARGE syndrome

Congenital diaphragmatic hernia (CDH) has been rarely described in CHARGE syndrome. We report a patient affected by CHARGE syndrome presenting with a right-sided Bochdalek-type diaphragmatic hernia, and collect the pertinent literature. Furthermore, we review the embryogenesis of the diaphragm and the pathogenesis of CDH to highlight if this malformation could be explained by a developmental anomaly of CHARGE. On the basis of our study, we suggest that patients affected by CDH, facial asymmetry and cardiovascular or urogenital malformations, should be actively screened for CHARGE syndrome findings.

Developmental abnormalities of the optic nerve and chiasm

Developmental anomalies of the optic nerve are an important and growing cause of lifelong visual handicap and they are often associated with systemic abnormalities. This review focuses on the ocular and systemic aspects of developmental anomalies arising from defects of fetal fissure closure and retinal ganglion cell development, and covers some other optic-disc anomalies that have systemic significance.

CHARGE syndrome: an update

CHARGE syndrome is a rare, usually sporadic autosomal dominant disorder due in 2/3 of cases to mutations within the CHD7 gene. The clinical definition has evolved with time. The 3C triad (Coloboma-Choanal atresia-abnormal semicircular Canals), arhinencephaly and rhombencephalic dysfunctions are now considered the most important and constant clues to the diagnosis. We will discuss here recent aspects of the phenotypic delineation of CHARGE syndrome and highlight the role of CHD7 in its pathogeny. We review available data on its molecular pathology as well as cytogenetic and molecular evidences for genetic heterogeneity within CHARGE syndrome.

CHARGE syndrome

CHARGE syndrome was initially defined as a non-random association of anomalies (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, Ear anomalies/deafness). In 1998, an expert group defined the major (the classical 4C's: Choanal atresia, Coloboma, Characteristic ears and Cranial nerve anomalies) and minor criteria of CHARGE syndrome. Individuals with all four major characteristics or three major and three minor characteristics are highly likely to have CHARGE syndrome. However, there have been individuals genetically identified with CHARGE syndrome without the classical choanal atresia and coloboma. The reported incidence of CHARGE syndrome ranges from 0.1-1.2/10,000 and depends on professional recognition. Coloboma mainly affects the retina. Major and minor congenital heart defects (the commonest cyanotic heart defect is tetralogy of Fallot) occur in 75-80% of patients. Choanal atresia may be membranous or bony; bilateral or unilateral. Mental retardation is variable with intelligence quotients (IQ) ranging from normal to profound retardation. Under-development of the external genitalia is a common finding in males but it is less apparent in females. Ear abnormalities include a classical finding of unusually shaped ears and hearing loss (conductive and/or nerve deafness that ranges from mild to severe deafness). Multiple cranial nerve dysfunctions are common. A behavioral phenotype for CHARGE syndrome is emerging. Mutations in the CHD7 gene (member of the chromodomain helicase DNA protein family) are detected in over 75% of patients with CHARGE syndrome. Children with CHARGE syndrome require intensive medical management as well as numerous surgical interventions. They also need multidisciplinary follow up. Some of the hidden issues of CHARGE syndrome are often forgotten, one being the feeding adaptation of these children, which needs an early aggressive approach from a feeding team. As the child develops, challenging behaviors become more common and require adaptation of educational and therapeutic services, including behavioral and pharmacological interventions.

Ocular coloboma: a reassessment in the age of molecular neuroscience

Congenital colobomata of the eye are important causes of childhood visual impairment and blindness. Ocular coloboma can be seen in isolation and in an impressive number of multisystem syndromes, where the eye phenotype is often seen in association with severe neurological or craniofacial anomalies or other systemic developmental defects. Several studies have shown that, in addition to inheritance, environmental influences may be causative factors. Through work to identify genes underlying inherited coloboma, significant inroads are being made into understanding the molecular events controlling closure of the optic fissure. In general, severity of disease can be linked to the temporal expression of the gene, but this is modified by factors such as tissue specificity of gene expression and genetic redundancy.

Phenotypic spectrum of CHARGE syndrome in fetuses with CHD7 truncating mutations correlates with expression during human development

BACKGROUND

The acronym CHARGE refers to a non-random cluster of malformations including coloboma, heart malformation, choanal atresia, retardation of growth and/or development, genital anomalies, and ear anomalies. This set of multiple congenital anomalies is frequent, despite rare patients with normal intelligence, and prognosis remains poor. Recently, CHD7 gene mutations have been identified in CHARGE patients; however, the function of CHD7 during development remains unknown.

METHODS

We studied a series of 10 antenatal cases in whom the diagnosis of CHARGE syndrome was suspected, considering that a careful pathological description would shed light on the CHD7 function during development. CHD7 sequence analysis and in situ hybridisation were employed.

RESULTS

The diagnosis of CHARGE syndrome was confirmed in all 10 fetuses by the identification of a CHD7 heterozygous truncating mutation. Interestingly, arhinencephaly and semi-circular canal agenesis were two constant features which are not included in formal diagnostic criteria so far. In situ hybridisation analysis of the CHD7 gene during early human development emphasised the role of CHD7 in the development of the central nervous system, internal ear, and neural crest of pharyngeal arches, and more generally showed a good correlation between specific CHD7 expression pattern and the developmental anomalies observed in CHARGE syndrome.

CONCLUSIONS

These results allowed us to further refine the phenotypic spectrum of developmental anomalies resulting from CHD7 dysfunction.

Behavioral profiles and symptoms of autism in CHARGE syndrome: preliminary Canadian epidemiological data

Individuals with CHARGE syndrome were identified through the Canadian Pediatric Surveillance Program (CPSP). From this population-based cohort (n=78), we present data on developmental and behavioral characteristics for the first 13 individuals (eight males, five females) for whom assessments are complete. Standardized parent questionnaires on development and behavior were followed by a structured telephone interview, with a specific emphasis on symptoms of autistic spectrum disorder (ASD). Preliminary results confirm that individuals with CHARGE syndrome have relatively low adaptive behavior skills, motor impairments being particularly significant. Most individuals did not present with significant behavior problems; however, evidence of ASD symptoms was judged to be moderate to strong in six of the ten children who were above the age of 4-5 years. Results are discussed with reference to the challenges inherent in the diagnosis of autism in individuals with sensory impairments, and to the implications for understanding the etiology of CHARGE syndrome and of ASD.

Adolescent and adult issues in CHARGE syndrome

Very little information has been published about adolescents and older individuals with Coloboma, Heart defects, Atresia choanae, Retarded growth and development, Genital hypoplasia, Ear anomalies and deafness (CHARGE) syndrome. This paper describes the results of a study that identifies the unique issues faced by adolescents and adults with CHARGE. Descriptive information was gathered from parents of patients with CHARGE, and/or the patients themselves, about their developmental, medical, educational, and social history. The resulting body of information provides important insights into the prognosis and special needs of individuals with CHARGE, as well as further research questions.

CHARGE association in Sweden: Malformations and functional deficits

CHARGE association (CA) consists of a non-random association of ocular coloboma (C), heart anomaly (H), atresia of choanae (A), retarded growth and/or development (R), genital hypoplasia (G), and ear anomalies and/or hearing impairment (E). A prospective multidisciplinary study of 31 Swedish patients with CA was undertaken in order to describe the associated malformations and functional deficits, find possible etiological factors and identify critical time periods for the maldevelopment. The clinical files were analyzed, the mothers answered a questionnaire on history of prenatal events, and a clinical evaluation of systemic findings, vision, hearing, balance, speech, oral and swallowing function, and neuro-psychiatric function, especially autism, was performed. The most frequent physical abnormalities affected ears (90%), eyes (90%), brain (61%), heart (52%), retarded growth (48%), genitals (38%), choanae (35%), and facial nerve (32%). Sixty-one percent of the patients were visually impaired or blind, and 74% had hearing loss or deafness. Problems in balance, speech, and eating were common. Forty percent of the patients had autism/atypical autism, and 82% had developmental delay. Three children were born following assisted fertilization and two mothers had diabetes. The mothers reported infections, bleedings, and drug use during pregnancy. Analysis of possible critical time periods suggested that most malformations were produced early in pregnancy, mainly during post conceptual weeks 4, 5, and 6. A multidisciplinary approach is essential in the assessment and management of CA.

CHARGE syndrome from birth to adulthood: An individual reported on from 0 to 33 years

CHARGE syndrome was independently reported by Hall [(1979): J Pediatr 95:395-398] and Hittner et al. [(1979): J Pediatr Ophthalmol Strabismus 16:122-128] and was initially considered to be a non-random association between distinct multiple congenital anomalies. It is now considered to be a recognizable syndrome with well-characterized diagnostic criteria and a genetic pathogenesis. We report on a 33-year-old adult male with CHARGE syndrome, with emphasis on the unique medical, behavioral, and psychological issues faced in adulthood. Characteristic facial and ear abnormalities were obvious in early childhood, and bilateral retinal colobomata, left choanal atresia, right congenital hip dislocation, and hypogonadism were diagnosed during the first year. Walking was delayed due to vestibular problems, speech was impaired due to moderately severe hearing loss, and use of sign communication was limited. Choanal atresia was surgically corrected in infancy, and atrial septal defect, ventricular septal defect, and patent ductus arteriosus were surgically corrected in childhood. Undescended testes were removed in adolescence, and gallstones were removed in early adulthood. Puberty was delayed until hormone replacement therapy began at 15 years. Behavioral disturbances and anxiety persisted throughout childhood, adolescence, and into adulthood, often resulting from communication challenges. At 33 years of age, he lives independently in a supervised group home, receives regular eye check-ups and is being monitored for severely reduced bone density.

Congenital disorders of the optic nerve: excavations and hypoplasia

The principal congenital abnormalities of the optic disc that can significantly impair visual function are excavation of the optic disc and optic nerve hypoplasia. The excavated optic disc abnormalities comprise optic disc coloboma, morning glory syndrome, and peripapillary staphyloma. Optic nerve hypoplasia manifests as a small optic nerve, which may or may not be accompanied by a peripapillary ring (the double ring sign). In addition, the optic disc cupping, which occurs as a sequel to some cases of periventricular leucomalacia, can arguably be classified as a type of optic nerve hypoplasia. All of these conditions can be unilateral or bilateral and can impair visual function mildly or severely. It is essential that children with poor vision due to any of these conditions are managed by treating refractive errors, giving occlusion therapy in selected cases, and optimising the conditions at home and at school in an attempt to ensure that impaired vision does not impede development or education.

Ribosomal protein L24 defect in belly spot and tail (Bst), a mouse Minute

Ribosomal protein mutations, termed Minutes, have been instrumental in studying the coordination of cell and tissue growth in Drosophila. Although abundant in flies, equivalent defects in mammals are relatively unknown. Belly spot and tail (Bst) is a semidominant mouse mutation that disrupts pigmentation, somitogenesis and retinal cell fate determination. Here, we identify Bst as a deletion within the Rpl24 riboprotein gene. Bst significantly impairs Rpl24 splicing and ribosome biogenesis. Bst/+ cells have decreased rates of protein synthesis and proliferation, and are outcompeted by wild-type cells in C57BLKS<-->ROSA26 chimeras. Bacterial artificial chromosome (BAC) and cDNA transgenes correct the mutant phenotypes. Our findings establish Bst as a mouse Minute and provide the first detailed characterization of a mammalian ribosomal protein mutation.

Autism associated with conditions characterized by developmental errors in early embryogenesis: a mini review

Autism is a complex developmental disorder without an established single etiology but with significant contributions from genetic studies, functional research, and neuropsychiatric and neuroradiologic investigations. The purpose of this paper is to review the findings in five studies involving individuals manifesting the characteristic findings of autism spectrum disorder associated with malformations and dysfunctions known to result from early embryogenic defects. These investigations include two associated with teratogens (thalidomide embryopathy, Mobius sequence with misoprostol) and three (most Mobius sequence cases, CHARGE association, Goldenhar syndrome) with no known etiology. These studies suggest that early embryonic development errors often involving cranial nerve palsies, internal and external ear malformations, ophthalmologic anomalies, and a variety of systemic malformations may be associated with autism spectrum disorders statistically more frequently than expected in a normal population. Although the exact time of developmental insult for each condition cannot be identified, the evidence is that it may occur as early as week 4 to 6+ of embryogenesis.

Autism with ophthalmologic malformations: the plot thickens

PURPOSE

To review the association of autism spectrum disorder (ASD) in individuals manifesting thalidomide embryopathy and Möbius sequence and compare them with three new studies in which ASD was also associated with ocular and systemic malformations: (1) a Swedish study of individuals with CHARGE association (Coloboma, Heart, choanal Atresia, developmental or growth Retardation, Genital anomaly, and Ear involvement); (2) a Swedish study of Goldenhar syndrome; and (3) Brazilian Möbius syndrome (sequence) study.

METHODS

In the Swedish CHARGE study, 31 patients met the inclusion criteria (3+ or 4 of the common characteristics of the CHARGE syndrome). The same team of investigators also evaluated 20 Swedish patients with Goldenhar syndrome. In the Brazilian Möbius study, 28 children with a diagnosis of Möbius sequence were studied; some children had a history of exposure during their mother's pregnancy to the abortifacient drug misoprostol in an unsuccessful abortion attempt.

RESULTS

In the CHARGE study, five patients had the more severe autism disorder and five had autistic-like condition. In the Goldenhar study, two had autism disorder and one had autistic-like condition. In the Brazilian Möbius study, the systemic findings of the misoprostol-exposed and misoprostol-unexposed patients were almost undistinguishable, and ASD was present in both groups (autism disorder in five and autistic-like condition in three).

CONCLUSION

Autism spectrum disorder has been reported in two conditions with known early pregnancy exposure to the teratogenic agents thalidomide and misoprostol. In the Brazilian Möbius study, autism also occurred in both the misoprostol-exposed and misoprostol-unexposed groups. Autism also was present in patients with both CHARGE association and Goldenhar syndrome.