Noncoding variants alter GATA2 expression in rhombomere 4 motor neurons and cause dominant hereditary congenital facial paresis

Hereditary congenital facial paresis type 1 (HCFP1) is an autosomal dominant disorder of absent or limited facial movement that maps to chromosome 3q21-q22 and is hypothesized to result from facial branchial motor neuron (FBMN) maldevelopment. In the present study, we report that HCFP1 results from heterozygous duplications within a neuron-specific GATA2 regulatory region that includes two enhancers and one silencer, and from noncoding single-nucleotide variants (SNVs) within the silencer. Some SNVs impair binding of NR2F1 to the silencer in vitro and in vivo and attenuate in vivo enhancer reporter expression in FBMNs. Gata2 and its effector Gata3 are essential for inner-ear efferent neuron (IEE) but not FBMN development. A humanized HCFP1 mouse model extends Gata2 expression, favors the formation of IEEs over FBMNs and is rescued by conditional loss of Gata3. These findings highlight the importance of temporal gene regulation in development and of noncoding variation in rare mendelian disease.

Pathogenic genetic variants identified in Australian families with paediatric cataract

Objective

Paediatric (childhood or congenital) cataract is an opacification of the normally clear lens of the eye and has a genetic basis in at least 18% of cases in Australia. This study aimed to replicate clinical gene screening to identify variants likely to be causative of disease in an Australian patient cohort.

Methods and analysis

Sixty-three reported isolated cataract genes were screened for rare coding variants in 37 Australian families using genome sequencing.

Results

Disease-causing variants were confirmed in eight families with variant classification as ‘likely pathogenic’. This included novel variants PITX3 p.(Ter303LeuextTer100), BFSP1 p.(Glu375GlyfsTer2), and GJA8 p.(Pro189Ser), as well as, previously described variants identified in genes GJA3, GJA8, CRYAA, BFSP1, PITX3, COL4A1 and HSF4. Additionally, eight variants of uncertain significance with evidence towards pathogenicity were identified in genes: GJA3, GJA8, LEMD2, PRX, CRYBB1, BFSP2, and MIP.

Conclusion

These findings expand the genotype–phenotype correlations of both pathogenic and benign variation in cataract-associated genes. They further emphasise the need to develop additional evidence such as functional assays and variant classification criteria specific to paediatric cataract genes to improve interpretation of variants and molecular diagnosis in patients.

The Global Retinoblastoma Outcome Study: a prospective, cluster-based analysis of 4064 patients from 149 countries

Background

Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival.

Methods

We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models.

Findings

The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope).

Interpretation

This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.

Funding

Queen Elizabeth Diamond Jubilee Trust.

Not just a chalazion-focal eyelid and orbital infection with Saksaenea vasiformis in an immunocompetent child

We present the case of a 2-year-old immunocompetent boy who presented with subacute right-sided orbital cellulitis due to Saksaenea vasiformis infection. Initial differential diagnoses included chalazion and localized soft tissue malignancy. There was no history of trauma. Immunological review and investigations were unremarkable. He was treated with a total of 3 months of antifungal therapy. Following resolution, he had two episodes of spontaneously resolving localized eyelid erythema at 2 and 8 months.

Recessive variants in COL25A1 gene as novel cause of arthrogryposis multiplex congenita with ocular congenital cranial dysinnervation disorder

A proper interaction between muscle-derived collagen XXV and its motor neuron-derived receptors protein tyrosine phosphatases σ and δ (PTP σ/δ) is indispensable for intramuscular motor innervation. Despite this, thus far, pathogenic recessive variants in the COL25A1 gene had only been detected in a few patients with isolated ocular congenital cranial dysinnervation disorders. Here we describe five patients from three unrelated families with recessive missense and splice site COL25A1 variants presenting with a recognizable phenotype characterized by arthrogryposis multiplex congenita with or without an ocular congenital cranial dysinnervation disorder phenotype. The clinical features of the older patients remained stable over time, without central nervous system involvement. This study extends the phenotypic and genotypic spectrum of COL25A1 related conditions, and further adds to our knowledge of the complex process of intramuscular motor innervation. Our observations indicate a role for collagen XXV in regulating the appropriate innervation not only of extraocular muscles, but also of bulbar, axial, and limb muscles in the human.

Infantile hemangioma affecting the iris

An infant girl developed a hemangioma affecting her left iris concurrently with diffuse cutaneous infantile hemangiomas from day 2 of life. Intraocular hemangiomas are rarely reported and are usually associated with neonatal hemangiomatosis, the presence of which indicates a high risk for visceral lesions. This striking case highlights the unusual clinical presentation of iris hemangioma and demonstrates the importance of conducting visceral screening when faced with these lesions. Oral propranolol was commenced and resulted in rapid improvement of all lesions without complication.

A 127 kb truncating deletion of PGRMC1 is a novel cause of X-linked isolated paediatric cataract

Inherited paediatric cataract is a rare Mendelian disease that results in visual impairment or blindness due to a clouding of the eye's crystalline lens. Here we report an Australian family with isolated paediatric cataract, which we had previously mapped to Xq24. Linkage at Xq24-25 (LOD = 2.53) was confirmed, and the region refined with a denser marker map. In addition, two autosomal regions with suggestive evidence of linkage were observed. A segregating 127 kb deletion (chrX:g.118373226_118500408del) in the Xq24-25 linkage region was identified from whole-genome sequencing data. This deletion completely removed a commonly deleted long non-coding RNA gene LOC101928336 and truncated the protein coding progesterone receptor membrane component 1 (PGRMC1) gene following exon 1. A literature search revealed a report of two unrelated males with non-syndromic intellectual disability, as well as congenital cataract, who had contiguous gene deletions that accounted for their intellectual disability but also disrupted the PGRMC1 gene. A morpholino-induced pgrmc1 knockdown in a zebrafish model produced significant cataract formation, supporting a role for PGRMC1 in lens development and cataract formation. We hypothesise that the loss of PGRMC1 causes cataract through disrupted PGRMC1-CYP51A1 protein-protein interactions and altered cholesterol biosynthesis. The cause of paediatric cataract in this family is the truncating deletion of PGRMC1, which we report as a novel cataract gene.

Changed ophthalmic workload following introduction of digital retinal photography for retinopathy of prematurity screening

BACKGROUND

ROP screening is vital in care of premature infants but is considered burdensome, difficult and time consuming for ophthalmologists. This study assessed the reduction in workload following the introduction of nurse-led WFDRI to a large neonatal nursery.

METHODS

We report a retrospective audit of 628 infants screened for ROP in the years 2010, 2013 and 2019 at the Royal Women's Hospital, Victoria. The last complete year of screening for ROP using binocular indirect ophthalmoscopy (BIO) alone (2010) was compared with two subsequent years after the introduction of nurse-led WFDRI. The main outcome measures were the time taken to report and document WFDRI and the time taken to undertake BIO examination of a premature infant and document the results.

RESULTS

The ophthalmologist's time taken to conduct BIO, review images and document the results per 100 patient examinations was reduced from 16.7 hours before introduction of WFDRI to 3.7 hours. Similarly, the weekly time spent on this component of ROP screening fell from 2.3 hours per week to 0.8 and 1.0 hours per week after introduction of WFDRI.

CONCLUSIONS

The introduction of nurse-led WFDRI has resulted in a dramatic and sustained reduction in ophthalmologist workload involved in ROP screening in a large Australian neonatal nursery. This may result in improved retention of the ophthalmic workforce required to undertake ROP screening.

Childhood and Early Onset Glaucoma Classification and Genetic Profile in a Large Australasian Disease Registry

PURPOSE

To report the relative frequencies of childhood and early onset glaucoma subtypes and their genetic findings in a large single cohort.

DESIGN

Retrospective clinical and molecular study.

PARTICIPANTS

All individuals with childhood glaucoma (diagnosed 0 to <18 years) and early onset glaucoma (diagnosed 18 to <40 years) referred to a national disease registry.

METHODS

We retrospectively reviewed the referrals of all individuals with glaucoma diagnosed at <40 years of age recruited to the Australian and New Zealand Registry of Advanced Glaucoma (ANZRAG). Subtypes of glaucoma were determined using the Childhood Glaucoma Research Network (CGRN) classification system. DNA extracted from blood or saliva samples underwent sequencing of genes associated with glaucoma.

MAIN OUTCOME MEASURES

The phenotype and genotype distribution of glaucoma diagnosed at <40 years of age.

RESULTS

A total of 290 individuals (533 eyes) with childhood glaucoma and 370 individuals (686 eyes) with early onset glaucoma were referred to the ANZRAG. Primary glaucoma was the most prevalent condition in both cohorts. In the childhood cohort, 57.6% of individuals (167/290, 303 eyes) had primary congenital glaucoma (PCG), and 19.3% (56/290, 109 eyes) had juvenile open-angle glaucoma. Juvenile open-angle glaucoma constituted 73.2% of the early onset glaucoma cohort (271/370, 513 eyes). Genetic testing in probands resulted in a diagnostic yield of 24.7% (125/506) and a reclassification of glaucoma subtype in 10.4% of probands (13/125). The highest molecular diagnostic rate was achieved in probands with glaucoma associated with nonacquired ocular anomalies (56.5%). Biallelic variants in CYP1B1 (n = 29, 23.2%) and heterozygous variants in MYOC (n = 24, 19.2%) and FOXC1 (n = 21, 16.8%) were most commonly reported among probands with a molecular diagnosis. Biallelic CYP1B1 variants were reported in twice as many female individuals as male individuals with PCG (66.7% vs. 33.3%, P = 0.02).

CONCLUSIONS

We report on the largest cohort of individuals with childhood and early onset glaucoma from Australasia using the CGRN classification. Primary glaucoma was most prevalent. Genetic diagnoses ascertained in 24.7% of probands supported clinical diagnoses and genetic counseling. International collaborative efforts are required to identify further genes because the majority of individuals still lack a clear molecular diagnosis.

Parent satisfaction and acceptability of telehealth consultations in pediatric ophthalmology: initial experience during the COVID-19 pandemic

Telehealth in pediatric ophthalmology has predominantly been utilized and reported in the setting of clinician-to-clinician opinion or store-and-forward of images, particularly in the diagnosis and management of retinopathy of prematurity (ROP). We present our initial experience of using a telehealth model of care to deliver real-time specialist pediatric ophthalmology services during the COVID-19 pandemic. Over a 5-week period, parents were invited to complete an anonymous survey following a telehealth ophthalmology consultation for their child. The survey explored their satisfaction, acceptance, and feedback relating to their experience. With an overall response rate of 49.4%, satisfaction was high (43.8% very satisfied; 38.2% satisfied). Most parents (71.9%) would consider telehealth for future ophthalmology consultations for their child.

Recurrent Rare Copy Number Variants Increase Risk for Esotropia

Purpose

To determine whether rare copy number variants (CNVs) increase risk for comitant esotropia.

Methods

CNVs were identified in 1614 Caucasian individuals with comitant esotropia and 3922 Caucasian controls from Illumina SNP genotyping using two Hidden Markov model (HMM) algorithms, PennCNV and QuantiSNP, which call CNVs based on logR ratio and B allele frequency. Deletions and duplications greater than 10 kb were included. Common CNVs were excluded. Association testing was performed with 1 million permutations in PLINK. Significant CNVs were confirmed with digital droplet polymerase chain reaction (ddPCR). Whole genome sequencing was performed to determine insertion location and breakpoints.

Results

Esotropia patients have similar rates and proportions of CNVs compared with controls but greater total length and average size of both deletions and duplications. Three recurrent rare duplications significantly (P = 1 × 10⁻⁶) increase the risk of esotropia: chromosome 2p11.2 (hg19, 2:87428677-87965359), spanning one long noncoding RNA (lncRNA) and two microRNAs (OR 14.16; 95% confidence interval [CI] 5.4–38.1); chromosome 4p15.2 (hg19, 4:25554332-25577184), spanning one lncRNA (OR 11.1; 95% CI 4.6–25.2); chromosome 10q11.22 (hg19, 10:47049547-47703870) spanning seven protein-coding genes, one lncRNA, and four pseudogenes (OR 8.96; 95% CI 5.4–14.9). Overall, 114 cases (7%) and only 28 controls (0.7%) had one of the three rare duplications. No case nor control had more than one of these three duplications.

Conclusions

Rare CNVs are a source of genetic variation that contribute to the genetic risk for comitant esotropia, which is likely polygenic. Future research into the functional consequences of these recurrent duplications may shed light on the pathophysiology of esotropia.

Global Retinoblastoma Presentation and Analysis by National Income Level

Importance

Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale.

Objectives

To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis.

Design, Setting, and Participants

A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017.

Main Outcomes and Measures

Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis.

Results

The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]).

Conclusions and Relevance

This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs.

Prevalence of FOXC1 Variants in Individuals With a Suspected Diagnosis of Primary Congenital Glaucoma

Importance

Both primary and secondary forms of childhood glaucoma have many distinct causative mechanisms, and in many cases a cause is not immediately clear. The broad phenotypic spectrum of secondary glaucoma, particularly in individuals with variants in FOXC1 or PITX2 genes associated with Axenfeld-Rieger syndrome, makes it more difficult to diagnose patients with milder phenotypes. These cases are occasionally classified and managed as primary congenital glaucoma.

Objective

To investigate the prevalence of FOXC1 variants in participants with a suspected diagnosis of primary congenital glaucoma.

Design, Setting, and Participants

Australian and Italian cohorts were recruited from January 1, 2007, through March 1, 2016. Australian individuals were recruited through the Australian and New Zealand Registry of Advanced Glaucoma and Italian individuals through the Genetic and Ophthalmology Unit of l'Azienda Socio-Sanitaria Territoriale Grande Ospedale Metropolitano Niguarda in Milan, Italy. We performed exome sequencing, in combination with Sanger sequencing and multiplex ligation-dependent probe amplification, to detect variants of FOXC1 in individuals with a suspected diagnosis of primary congenital glaucoma established by their treating specialist. Data analysis was completed from June 2015 to November 2017.

Main Outcome and Measures

Identification of single-nucleotide and copy number variants in FOXC1, along with phenotypic characterization of the individuals who carried them.

Results

A total of 131 individuals with a suspected diagnosis of primary congenital glaucoma were included. The mean (SD) age at recruitment in the Australian cohort was 24.3 (18.1) years; 37 of 84 Australian participants (44.0%) were female, and 71 of 84 (84.5%) were of European ancestry. The mean (SD) age at recruitment was 22.5 (18.4) years in the Italian cohort; 21 of 47 Italian participants (44.7%) were female, and 45 of 47 (95.7%) were of European ancestry. We observed rare, predicted deleterious FOXC1 variants in 8 of 131 participants (6.1%), or 8 of 166 participants (4.8%) when including those explained by variants in CYP1B1. On reexamination or reinvestigation, all of these individuals had at least 1 detectable ocular and/or systemic feature associated with Axenfeld-Rieger syndrome.

Conclusions and Relevance

These data highlight the genetic and phenotypic heterogeneity of childhood glaucoma and support the use of gene panels incorporating FOXC1 as a diagnostic aid, especially because clinical features of Axenfeld-Rieger syndrome can be subtle. Further replication of these results will be needed to support the future use of such panels.

Biallelic CPAMD8 Variants Are a Frequent Cause of Childhood and Juvenile Open-Angle Glaucoma

PURPOSE

Developmental abnormalities of the ocular anterior segment in some cases can lead to ocular hypertension and glaucoma. CPAMD8 is a gene of unknown function recently associated with ocular anterior segment dysgenesis, myopia, and ectopia lentis. We sought to assess the contribution of biallelic CPAMD8 variants to childhood and juvenile open-angle glaucoma.

DESIGN

Retrospective, multicenter case series.

PARTICIPANTS

A total of 268 probands and their relatives with a diagnosis of childhood or juvenile open-angle glaucoma.

PURPOSE

Developmental abnormalities of the ocular anterior segment in some cases can lead to ocular hypertension and glaucoma. CPAMD8 is a gene of unknown function recently associated with ocular anterior segment dysgenesis, myopia, and ectopia lentis. We sought to assess the contribution of biallelic CPAMD8 variants to childhood and juvenile open-angle glaucoma.

METHODS

Patients underwent a comprehensive ophthalmic assessment, with DNA from patients and their relatives subjected to genome, exome, or capillary sequencing. CPAMD8 RNA expression analysis was performed on tissues dissected from cadaveric human eyes.

MAIN OUTCOME MEASURES

Diagnostic yield within a cohort of childhood and juvenile open-angle glaucoma, prevalence and risk of ophthalmic phenotypes, and relative expression of CPAMD8 in the human eye.

RESULTS

We identified rare (allele frequency < 4×10^-5) biallelic CPAMD8 variants in 5.7% (5/88) of probands with childhood glaucoma and 2.1% (2/96) of probands with juvenile open-angle glaucoma. When including family members, we identified 11 individuals with biallelic variants in CPAMD8 from 7 unrelated families. Nine of these individuals were diagnosed with glaucoma (9/11, 81.8%), with a mean age at diagnosis of 9.22±14.89 years, and all individuals with glaucoma required 1 or more incisional procedures to control high intraocular pressure. Iris abnormalities were observed in 9 of 11 individuals, cataract was observed in 8 of 11 individuals (72.7%), and retinal detachment was observed in 3 of 11 individuals (27.3%). CPAMD8 expression was highest in neural crest-derived tissues of the adult anterior segment, suggesting that CPAMD8 variation may cause malformation or obstruction of key drainage structures.

CONCLUSIONS

Biallelic CPAMD8 variation was associated with a highly heterogeneous phenotype and in our cohorts was the second most common inherited cause of childhood glaucoma after CYP1B1 and juvenile open-angle glaucoma after MYOC. CPAMD8 sequencing should be considered in the investigation of both childhood and juvenile open-angle glaucoma, particularly when associated with iris abnormalities, cataract, or retinal detachment.

Acquired lacrimal drainage apparatus obstruction in children

BACKGROUND

Pediatric acquired lacrimal drainage apparatus (LDA) obstruction is much rarer than congenital LDA obstruction. Its etiology and treatment outcomes have not been well defined. Our aim was to examine the etiology and management of acquired LDA obstruction in children and report the results of its management.

METHODS

We retrospectively reviewed the medical records of patients ≤16 years of age who presented with acquired epiphora to investigate the causes and describe the management of this condition.

RESULTS

A total of 31 patients (16 males [52%]) were included. Mean age of patients was 10.9 years (range, 3-16). The main causes of acquired LDA obstruction were keratoconjunctivitis, herpes simplex blepharokeratoconjunctivitis, and trauma. Silicone tube intubation, endonasal or external dacryocystorhinostomy, and the insertion of lacrimal bypass tubes were the mainstays of management.

CONCLUSIONS

It is important to suspect acquired LDA obstruction in children with acquired, persistent epiphora. Surgical management is similar to that in adults.

Genome-Wide Association Study Identifies a Susceptibility Locus for Comitant Esotropia and Suggests a Parent-of-Origin Effect

Purpose

To identify genetic variants conferring susceptibility to esotropia. Esotropia is the most common form of comitant strabismus, has its highest incidence in European ancestry populations, and is believed to be inherited as a complex trait.

Methods

White European American discovery cohorts with nonaccommodative (826 cases and 2991 controls) or accommodative (224 cases and 749 controls) esotropia were investigated. White European Australian and United Kingdom cohorts with nonaccommodative (689 cases and 1448 controls) or accommodative (66 cases and 264 controls) esotropia were tested for replication. We performed a genome-wide case-control association study using a mixed linear additive model. Meta-analyses of discovery and replication cohorts were then conducted.

Results

A significant association with nonaccommodative esotropia was discovered (odds ratio [OR] = 1.41, P = 2.84 × 10-09) and replicated (OR = 1.23, P = 0.01) at rs2244352 [T] located within intron 1 of the WRB (tryptophan rich basic protein) gene on chromosome 21 (meta-analysis OR = 1.33, P = 9.58 × 10-11). This single nucleotide polymorphism (SNP) is differentially methylated, and there is a statistically significant skew toward paternal inheritance in the discovery cohort. Meta-analysis of the accommodative discovery and replication cohorts identified an association with rs912759 [T] (OR = 0.59, P = 1.89 × 10-08), an intergenic SNP on chromosome 1p31.1.

Conclusions

This is the first genome-wide association study (GWAS) to identify significant associations in esotropia and suggests a parent-of-origin effect. Additional cohorts will permit replication and extension of these findings. Future studies of rs2244352 and WRB should provide insight into pathophysiological mechanisms underlying comitant strabismus.

Etiology of pediatric acquired blepharoptosis

PURPOSE

To describe the etiology of acquired pediatric blepharoptosis in a large clinical series and to elucidate the causes of the disease.

METHODS

The medical records of all patients presenting with acquired blepharoptosis at two specialist ocular plastics practices and a pediatric ophthalmology practice during a period of up to 25 years were reviewed retrospectively and classified according to their diagnosis. Patients were grouped into children (<18 years), younger adults (18-40 years), and older adults (>40 years).

RESULTS

A total of 268 patients <18 years of age were identified. The most common identifiable causes of acquired blepharoptosis in children were infantile hemangioma (n = 92 [34.3%]) and trauma (n = 41 [15.3%]). In 42 cases (15.7%) a definite diagnosis could not be made.

CONCLUSIONS

The etiology of pediatric acquired blepharoptosis can frequently be determined by history and examination; additional diagnostic tests are sometimes required. A high percentage of pediatric patients have blepharoptosis of unknown cause.

Glaucoma spectrum and age-related prevalence of individuals with FOXC1 and PITX2 variants

This corrects the article DOI: 10.1038/ejhg.2017.59.

High-Throughput Genetic Screening of 51 Pediatric Cataract Genes Identifies Causative Mutations in Inherited Pediatric Cataract in South Eastern Australia

Pediatric cataract is a leading cause of childhood blindness. This study aimed to determine the genetic cause of pediatric cataract in Australian families by screening known disease-associated genes using massively parallel sequencing technology. We sequenced 51 previously reported pediatric cataract genes in 33 affected individuals with a family history (cases with previously known or published mutations were excluded) using the Ion Torrent Personal Genome Machine. Variants were prioritized for validation if they were predicted to alter the protein sequence and were absent or rare with minor allele frequency <1% in public databases. Confirmed mutations were assessed for segregation with the phenotype in all available family members. All identified novel or previously reported cataract-causing mutations were screened in 326 unrelated Australian controls. We detected 11 novel mutations in GJA3, GJA8, CRYAA, CRYBB2, CRYGS, CRYGA, GCNT2, CRYGA, and MIP; and three previously reported cataract-causing mutations in GJA8, CRYAA, and CRYBB2 The most commonly mutated genes were those coding for gap junctions and crystallin proteins. Including previous reports of pediatric cataract-associated mutations in our Australian cohort, known genes account for >60% of familial pediatric cataract in Australia, indicating that still more causative genes remain to be identified.

Aetiology of acquired blepharoptosis in young adults

PURPOSE

To identify the causes of blepharoptosis in young adults, and explore cases that do not fit into current diagnostic categories.

METHODS

A retrospective cohort study of all patients aged 18-40 years ("young adults") with acquired blepharoptosis that presented to two specialist ocular plastics practices and a paediatric ophthalmologist over a period of up to 25 years. Each patient was classified according to diagnosis. Where the diagnosis was uncertain, the files were examined in detail to try and further establish a cause.

RESULTS

A total of 266 young adult patients were included. The most common causes of acquired blepharoptosis were trauma-related (28.2%) and anophthalmic blepharoptosis (19.9%). In 12.4% of the cases, a definite diagnosis could not be made. Of these, one-third had a history of soft contact lens use, a possible etiologic factor.

CONCLUSIONS

The cause of acquired blepharoptosis can usually be established by an appropriate history and examination, with additional diagnostic tests sometimes required. Nearly half of all young adult ptosis is related to trauma or acquired anophthalmos. Around one in eight young adults have blepharoptosis of unknown cause, a group warranting further study.

Glaucoma spectrum and age-related prevalence of individuals with FOXC1 and PITX2 variants

Variation in FOXC1 and PITX2 is associated with Axenfeld-Rieger syndrome, characterised by structural defects of the anterior chamber of the eye and a range of systemic features. Approximately half of all affected individuals will develop glaucoma, but the age at diagnosis and the phenotypic spectrum have not been well defined. As phenotypic heterogeneity is common, we aimed to delineate the age-related penetrance and the full phenotypic spectrum of glaucoma in FOXC1 or PITX2 carriers recruited through a national disease registry. All coding exons of FOXC1 and PITX2 were directly sequenced and multiplex ligation-dependent probe amplification was performed to detect copy number variation. The cohort included 53 individuals from 24 families with disease-associated FOXC1 or PITX2 variants, including one individual diagnosed with primary congenital glaucoma and five with primary open-angle glaucoma. The overall prevalence of glaucoma was 58.5% and was similar for both genes (53.3% for FOXC1 vs 60.9% for PITX2, P=0.59), however, the median age at glaucoma diagnosis was significantly lower in FOXC1 (6.0±13.0 years) compared with PITX2 carriers (18.0±10.6 years, P=0.04). The penetrance at 10 years old was significantly lower in PITX2 than FOXC1 carriers (13.0% vs 42.9%, P=0.03) but became comparable at 25 years old (71.4% vs 57.7%, P=0.38). These findings have important implications for the genetic counselling of families affected by Axenfeld-Rieger syndrome, and also suggest that FOXC1 and PITX2 contribute to the genetic architecture of primary glaucoma subtypes.

Higher Rates of Retinopathy of Prematurity after Increasing Oxygen Saturation Targets for Very Preterm Infants: Experience in a Single Center

Randomized trials of oxygen saturation target ranges for extremely preterm infants showed increased survival but increased retinopathy of prematurity with higher compared with lower target ranges. In our center, changing from a target range of 88%-92% to 91%-95% has been associated with increased rates and severity of retinopathy of prematurity.

Occurrence of CYP1B1 Mutations in Juvenile Open-Angle Glaucoma With Advanced Visual Field Loss

IMPORTANCE

Juvenile open-angle glaucoma (JOAG) is a severe neurodegenerative eye disorder in which most of the genetic contribution remains unexplained.

OBJECTIVE

To assess the prevalence of pathogenic CYP1B1 sequence variants in an Australian cohort of patients with JOAG and severe visual field loss.

DESIGN, SETTING, AND PARTICIPANTS

For this cohort study, we recruited 160 patients with JOAG classified as advanced (n = 118) and nonadvanced (n = 42) through the Australian and New Zealand Registry of Advanced Glaucoma from January 1, 2007, through April 1, 2014. Eighty individuals with no evidence of glaucoma served as a control group. We defined JOAG as diagnosis before age 40 years and advanced JOAG as visual field loss in 2 of the 4 central fixation squares on a reliable visual field test result. We performed direct sequencing of the entire coding region of CYP1B1. Data analysis was performed in October 2014.

MAIN OUTCOMES AND MEASURES

Identification and characterization of CYP1B1 sequence variants.

RESULTS

We identified 7 different pathogenic variants among 8 of 118 patients with advanced JOAG (6.8%) but none among the patients with nonadvanced JOAG. Three patients were homozygous or compound heterozygous for CYP1B1 pathogenic variants, which provided a likely basis for their disease. Five patients were heterozygous. The allele frequency among the patients with advanced JOAG (11 in 236 [4.7%]) was higher than among our controls (1 in 160 [0.6%]; P = .02; odds ratio, 7.8 [95% CI, 0.02-1.0]) or among the control population from the Exome Aggregation Consortium database (2946 of 122 960 [2.4%]; P = .02; odds ratio, 2.0 [95% CI, 0.3-0.9]). Individuals with CYP1B1 pathogenic variants, whether heterozygous or homozygous, had worse mean (SD) deviation on visual fields (-24.5 [5.1] [95% CI, -31.8 to -17.2] vs -15.6 [10.0] [95% CI, -17.1 to -13.6] dB; F1,126 = 5.90; P = .02; partial ηp2 = 0.05) and were younger at diagnosis (mean [SD] age, 23.1 [8.4] [95% CI, 17.2-29.1] vs 31.5 [8.0] [95% CI, 30.1-33.0] years; F1,122 = 7.18; P = .008; ηp2 = 0.06) than patients without CYP1B1 pathogenic variants.

CONCLUSIONS AND RELEVANCE

Patients with advanced JOAG based on visual field loss had enrichment of CYP1B1 pathogenic variants and a more severe phenotype compared with unaffected controls and patients with nonadvanced JOAG.

CYP1B1 copy number variation is not a major contributor to primary congenital glaucoma

PURPOSE

To evaluate the prevalence and the diagnostic utility of testing for CYP1B1 copy number variation (CNV) in primary congenital glaucoma (PCG) cases unexplained by CYP1B1 point mutations in The Australian and New Zealand Registry of Advanced Glaucoma.

METHODS

In total, 50 PCG cases either heterozygous for disease-causing variants or with no CYP1B1 sequence variants were included in the study. CYP1B1 CNV was analyzed by Multiplex Ligation-dependent Probe Amplification (MLPA).

RESULTS

No deletions or duplications were found in any of the cases.

CONCLUSION

This is the first study to report on CYP1B1 CNV in PCG cases. Our findings show that this mechanism is not a major contributor to the phenotype and is of limited diagnostic utility.

Superselective intra-arterial chemotherapy for advanced retinoblastoma complicated by metastatic disease

We present a case of a child with unilateral group E retinoblastoma (according to the International Classification of Retinoblastoma) who received superselective intra-arterial chemotherapy as primary therapy. Although the tumor showed signs of regression, the patient developed orbital metastases requiring surgical excision and chemotherapy. Eventually the affected eye progressed to total retinal detachment and required enucleation.

Scedosporium prolificans endogenous endophthalmitis

Scedosporium prolificans is an opportunistic fungus with a predilection for sepsis and endophthalmitis in immunocompromised patients. We report a case of endogenous S. prolificans endophthalmitis in a 9-year-old girl following chemotherapy for acute myeloid leukemia. She achieved an excellent visual outcome following intensive antifungal therapy.

Familial Transmission Risk of Infantile Glaucoma in Australia

PURPOSE

Primary infantile glaucoma (PIG) is predominantly inherited as a recessive disease, whereas anterior segment dysgenesis (ASD) is usually dominantly inherited. The purpose of this study was to determine the likelihood of a person who has infantile glaucoma to produce a child who also manifests the disease.

METHODS

A retrospective cross-sectional design was utilized. The pedigrees of probands from south-eastern Australia diagnosed with infantile glaucoma since 1980 were reviewed. Cases were subdivided into two groups according to the presence or absence of ASD. Exclusion criteria included incomplete pedigree phenotype information or aphakic glaucoma following congenital cataract surgery. Fisher's exact test was used to compare the parent-offspring phenotype transmission between ASD-associated infantile glaucoma and PIG.

RESULTS

A total of 67 probands were identified; however, three pedigrees were excluded due to incomplete phenotype information. Direct parent-offspring transmission of phenotype was statistically significantly more common in ASD-associated infantile glaucoma (2/8) than in PIG (1/56) pedigrees (p = 0.039).

CONCLUSIONS

Although this study reveals that Australian patients with ASD-associated infantile glaucoma are at greater risk of having children with infantile glaucoma than patients with PIG, the number of ASD pedigrees with direct transmission of infantile glaucoma is lower than expected. Based on our population frequency analysis and the results of our study, the risk of PIG, if one parent is affected by PIG and the other is normal, is less than 2%.

Ophthalmologic presentation of oxidative phosphorylation diseases of childhood

To investigate ophthalmologic manifestations in children with definitive oxidative phosphorylation disorders, a retrospective review was conducted of clinical and laboratory records of all such pediatric patients (n = 103) diagnosed and treated at one center between 1983 and 2006. All were residents of Victoria, Australia. Nystagmus or roving eye movements were the most common ophthalmologic manifestations as a presenting symptom of disease (13/20) and were the sole manifestation at presentation in 10/13 patients. Divergent strabismus was a presenting symptom in 5/20 patients and was the sole manifestation at presentation in 3/20 patients. Abnormal eye movements were noted in 6 patients and strabismus was noted in 4 patients with Leigh's or Leigh-like disease; in 9 of these 10 patients, Leigh's disease was the result of complex I deficiency. Altogether, ophthalmologic manifestations were noted at presentation in 12/35 patients with complex I deficiency. External ophthalmoplegia in conjunction with ptosis was the presenting symptom in 3/20 patients, all with Kearns-Sayers syndrome. Patients suspected of having oxidative phosphorylation disorders should be referred for ophthalmologic examination. Prospective studies are needed for a comprehensive elucidation of the ophthalmologic findings in these disorders.

Management of congenital elevation deficiency due to congenital third nerve palsy and monocular elevation deficiency

PURPOSE

To document the presentation and management of congenital III nerve palsy and monocular elevation deficiency to single ophthalmologist over a 14-year period. Surgical management was reviewed and visual outcome was analysed.

METHODS

A retrospective study was conducted of all patients presenting during a period between 1992 and 2006 to the private practice of a paediatric ophthalmologist, with either congenital III or monocular elevation deficiency. For patients requiring surgical intervention pre- and post-surgical data were documented and analysed.

RESULTS

A total of 19 congenital III and 13 monocular elevation deficiency patients were identified. There were eight surgical patients in each congenital III nerve palsy group and in the monocular elevation deficiency group. The congenital III group had a preoperative mean exotropia for near of -36 prism dioptres (PD) compared with postoperative mean exotropia for near -16 PD. Preoperative mean hypotropia for near of -19 PD was improved to postoperative mean hypotropia of -5 PD. The monocular elevation deficiency group had preoperative mean esotropia for near of +6 PD compared with postoperative mean exotropia for near -5 PD. Preoperative mean hypotropia for near of -15 PD was improved to postoperative mean hypotropia of -7 PD. At last follow up both groups had a majority of mild or no amblyopia noted.

CONCLUSION

Superficially, congenital III and monocular elevation deficiency may appear similar, both frequently having ptosis and hypotropia as features. Careful clinical assessment of the horizontal alignment and the result of forced duction testing will usually allow them to be distinguished. Congenital III more frequently requires surgery for exotropia as well as surgery for hypotropia and monocular elevation deficiency more often requires surgery just for hypotropia. The ptosis surgery is similar for either diagnosis in this study. Significant cosmetic improvement, as well as excellent visual acuity outcomes can be achieved.

Prevalence of CYP1B1 mutations in Australian patients with primary congenital glaucoma

Analysis of CYP1B1 in primary congenital glaucoma (PCG) patients from various ethnic populations indicates that allelic heterogeneity is high, and some mutations are population specific. No study has previously reported the rate or spectrum of CYP1B1 mutations in Australian PCG patients. The aim of this study is to determine the frequency of CYP1B1 mutations in our predominately Caucasian, Australian cohort of PCG cases. Thirty-seven probands were recruited from South-Eastern Australia, along with 100 normal control subjects. Genomic DNA was extracted and the coding regions of CYP1B1 analysed by direct sequencing. Sequence analysis identified 10 different CYP1B1 disease-causing variants in eight probands (21.6%). Five subjects were compound heterozygotes, two subjects heterozygous and one homozygous for CYP1B1 mutations. Three missense mutations are novel (D192Y, G329D, and P400S). None of the novel mutations identified were found in normal controls. One normal control subject was heterozygous for the previously reported CYP1B1 R368H mutation. Six previously described probable polymorphisms were also identified. Mutations in CYP1B1 account for approximately one in five PCG cases from Australia. Our data also supported the high degree of allelic heterogeneity seen in similar studies from other ethnic populations, thereby underscoring the fact that other PCG-related genes remain to be identified.

Retrospective analysis of patients attending a neurofibromatosis type 1 clinic

AIM

To undertake a retrospective analysis of the patients who attended the neurofibromatosis type 1 clinic (NF clinic) at the Royal Children's Hospital, Melbourne between March 2001 and May 2004. From this analysis, we aimed to ascertain the frequency and nature of complications of NF1 in this cohort and compare this with other large series.

METHODS

Genetic files and hospital records of patients who attended the NF clinic were reviewed. Data regarding the clinical features and NF1-related complications present in the patient population were entered into a database and then analysed.

RESULTS

Data were available for 121 patients with presumed or confirmed diagnoses of NF1 who attended the NF clinic between the study dates. While most patients were referred to the clinic for 'routine surveillance', complications of NF1 were common. Forty-four per cent of patients had learning difficulties, 21% had optic gliomas and 17% had plexiform neurofibromas. Fifty-five per cent of those with plexiform neurofibromas required at least one surgical procedure.

CONCLUSION

The NF clinic was accessed by patients of all ages to assist with diagnosis, provide routine surveillance and manage complex complications of NF1. The prevalence and range of complications of NF1 of the patients attending this clinic is similar to other large retrospective studies in tertiary centres.

Postmortem orbital findings in shaken baby syndrome

PURPOSE

To compare postmortem orbital findings in pediatric accidental head injury to Shaken Baby Syndrome (SBS).

DESIGN

Retrospective study.

METHODS

SETTING

Institutional.

STUDY POPULATION

Thirty-six patients underwent postmortem modified exenteration with sectioning of the orbital contents; 18 victims of SBS and 18 cases of fatal accidental head trauma.

OBSERVATION PROCEDURE

In all cases of children who died from accidental head trauma, the orbital tissues were separated to expose the optic nerve sheath. Patients with gross evidence of hemorrhage within the sheath were included. All cases of SBS were included. After accidental head injury, exenteration was performed only if optic nerve sheath hemorrhage was suspected on gross examination. All children younger than 18 years old with head injury as primary cause of death were included. SBS is defined as having at least two of the following: (1) typical abnormal findings on neuroimaging, (2) typical skeletal injury, (3) retinal hemorrhages, (4) history of abusive shaking with or without blunt head trauma, or (5) an inadequate history to explain the observed injuries.

MAIN OUTCOME MEASURE

Presence or absence of orbital hemorrhage.

RESULTS

Orbital tissue injury is more common in SBS than accidental head trauma without orbital fracture. In addition, optic nerve sheath and optic nerve intradural hemorrhage are also significantly more common in SBS (P < .0001).

CONCLUSIONS

Our study reports new evidence of injury to orbital tissues in SBS and supports the concept that these finding are due to unique acceleration-deceleration forces of this type of abusive head injury.

Two-year results of laser treatment for retinopathy of prematurity at a single neonatal intensive care unit

PURPOSE

To present the 2-year results of all patients receiving laser treatment for retinopathy of prematurity (ROP) at a single institution over a 9.5-year period. To establish the frequency of threshold ROP.

METHODS

Consecutive case series. All patients who had laser treatment for ROP at The Royal Women's Hospital, Melbourne, Australia, between January 1992 and July 2001 were prospectively recorded in a database. Their medical charts were retrospectively reviewed. Baseline birthweight, gestational age at birth, timing of treatment, and ROP severity at treatment were recorded. The main outcome measures were visual acuity (significantly reduced or not), anatomic outcome and refractive error at 2 years of age (corrected for the degree of prematurity).

RESULTS

A total of 107 eyes of 57 babies were treated with laser photocoagulation. Four children did not survive for follow-up, and 2-year follow-up data were available for 38 children (67%, 71 treated eyes). Average duration of follow-up was 26 months. Two-year visual acuity was significantly reduced in 12/71 (17%) treated eyes, and 3/38 children (8%) had significantly reduced vision in both eyes. An anatomical outcome of macular fold or worse was observed in 8/71 eyes (11%). Mean 2-year spherical equivalent refractive outcome was only minimally myopic (-0.6 D).

CONCLUSION

Visual, anatomic and refractive outcomes after laser treatment for ROP were favourable, confirming that laser photocoagulation is an effective treatment for severe ROP.

Primary trabeculodysgenesis in association with neonatal Marfan syndrome

We present the clinical and ophthalmological findings in two infants with neonatal Marfan syndrome (nMFS) and primary trabeculodysgenesis (PT). Fibrillin 1 (FBN1) mutations were confirmed in both cases. Numerous eye anomalies have been recognized in infants with nMFS, but PT has not been reported previously. Our report expands the phenotype of nMFS, and highlights the importance of early and careful ophthalmological assessment of these infants.

Primary infantile glaucoma in an Australian population

BACKGROUND

Primary infantile glaucoma presents rarely, but can be responsible for significant visual morbidity. There is little information on the clinical features and visual outcome of a pure population of primary infantile glaucoma, as opposed to a mixed population of primary and secondary glaucoma or combined group of those with trabeculodysgenesis and iridotrabeculodysgenesis.

METHODS

We conducted a retrospective review of children with primary infantile glaucoma seen in south-eastern Australia between 1980 and 2000, using The Royal Children's Hospital ophthalmic diagnostic coding database.

RESULTS

Fifty-one patients with primary infantile glaucoma were identified (83 eyes). This equates to an estimated incidence of approximately 1 in 30,000 births. The mean +/- SD age at presentation was 135 +/- 84 days. 'Burnt-out' disease (megalocornea without raised intraocular pressure) was diagnosed in 10.8%. Goniotomy was the most commonly performed surgical procedure (69.4% of 72 eyes). Surgical success with one or two goniotomies was achieved in 74% of eyes. Visual outcomes at final review were generally good with 61.8% reading 6/12 or better. There were a disproportionately high number of children having a final recorded acuity of <6/60 in the group diagnosed in the first 3 months of life.

CONCLUSIONS

Primary infantile glaucoma is a rare ocular condition in this population that presents at a mean age of 4.4 months. Surgical and visual outcomes are generally favourable.

Investigation of crystallin genes in familial cataract, and report of two disease associated mutations

AIMS

Mutations of seven crystallin genes have been shown to cause familial cataract. The authors aimed to identify disease causing crystallin mutations in paediatric cataract families from south eastern Australia.

METHODS

38 families with autosomal dominant or recessive paediatric cataract were examined. Three large families were studied by linkage analysis. Candidate genes at regions providing significant LOD scores were sequenced. Single stranded conformational polymorphism (SSCP) analysis was used to screen five crystallin genes in the probands, followed by direct sequencing of observed electrophoretic shifts. Mutations predicted to affect the coding sequence were subsequently investigated in the entire pedigree.

RESULTS

A LOD score of 3.72 was obtained at the gamma-crystallin locus in one pedigree. Sequencing revealed a P23T mutation of CRYGD, found to segregate with disease. A splice site mutation at the first base of intron 3 of the CRYBA1/A3 gene segregating with disease was identified by SSCP in another large family. Five polymorphisms were also detected.

CONCLUSIONS

Although mutations in the five crystallin genes comprehensively screened in this study account for 38% of paediatric cataract mutations in the literature, only two causative mutations were detected in 38 pedigrees, suggesting that crystallin mutations are a relatively rare cause of the cataract phenotype in this population.

Hereditary hyperferritinemia-cataract syndrome: prevalence, lens morphology, spectrum of mutations, and clinical presentations

OBJECTIVES

To provide a comprehensive description of the clinical presentations, cataract morphology, and molecular basis of hereditary hyperferritinemia-cataract syndrome (HHCS) in 4 Australian pedigrees and to estimate its prevalence.

METHODS

All known cases of HHCS in southeastern Australia were ascertained. Family members provided a medical history and underwent physical examination, lens photography, and venipuncture for measurement of serum ferritin levels and DNA extraction. Sequence analysis of the iron-responsive element of the ferritin light chain on chromosome 19q13.3-qter was performed.

RESULTS

We investigated 26 affected individuals from 5 Australian pedigrees. Two pedigrees with HHCS ascertained independently were subsequently found to form 1 large kindred carrying the mutation A40G. The minimum estimated prevalence of HHCS is 1/200000. One pedigree had the mutation G32C. Among 2 smaller pedigrees studied, one carried a novel mutation (C39A), and the other was identified through the 2-year-old propositus with cataract but no positive family history. The latter case was shown to be due to a de novo mutation (G32U). All cataracts were highly distinctive in morphology, consisting of slowly progressive flecks, vacuoles, and distinctive crystalline deposits scattered predominantly in the lens cortex but also in the nucleus. Eight of 18 affected individuals examined have required cataract extraction to date. No other identified clinical manifestations of HHCS were delineated.

CONCLUSIONS

Cataract morphology in HHCS is highly distinctive. Longitudinal observation demonstrated slow progression of the cataracts. This study highlights that, although HHCS is an autosomal dominant condition, the diagnosis should be considered even in sporadic cataract of typical morphology. Furthermore, individuals with unexplained hyperferritinemia should be referred for ophthalmological assessment, as the cataract may be asymptomatic but lead to a correct diagnosis of HHCS. Clinical Relevance Progressive cataracts of highly distinctive morphology are an important feature of HHCS. Evaluation for this type of cataract may be of diagnostic value in patients with unexplained hyperferritinemia. Hereditary hyperferritinemia-cataract syndrome can be a cause of cataracts in pediatric patients even in the absence of any positive family history.

Mutations in a novel gene, NHS, cause the pleiotropic effects of Nance-Horan syndrome, including severe congenital cataract, dental anomalies, and mental retardation

Nance-Horan syndrome (NHS) is an X-linked disorder characterized by congenital cataracts, dental anomalies, dysmorphic features, and, in some cases, mental retardation. NHS has been mapped to a 1.3-Mb interval on Xp22.13. We have confirmed the same localization in the original, extended Australian family with NHS and have identified protein-truncating mutations in a novel gene, which we have called "NHS," in five families. The NHS gene encompasses approximately 650 kb of genomic DNA, coding for a 1,630-amino acid putative nuclear protein. NHS orthologs were found in other vertebrates, but no sequence similarity to known genes was identified. The murine developmental expression profile of the NHS gene was studied using in situ hybridization and a mouse line containing a lacZ reporter-gene insertion in the Nhs locus. We found a complex pattern of temporally and spatially regulated expression, which, together with the pleiotropic features of NHS, suggests that this gene has key functions in the regulation of eye, tooth, brain, and craniofacial development.

Aetiology of congenital and paediatric cataract in an Australian population

BACKGROUND/AIM

Paediatric cataract is a major cause of childhood blindness. Several genes associated with congenital and paediatric cataracts have been identified. The aim was to determine the incidence of cataract in a population, the proportion of hereditary cataracts, the mode of inheritance, and the clinical presentation.

METHODS

The Royal Children's Hospital and the Royal Victorian Eye and Ear Hospital have a referral base for almost all paediatric patients with cataracts in south eastern Australia. The database contains cases seen over the past 25 years. The medical histories of these patients were reviewed.

RESULTS

421 patients with paediatric cataract were identified, which gives an estimated incidence of 2.2 per 10,000 births. Of the 342 affected individuals with a negative family history, 50% were diagnosed during the first year of life, and 56/342 (16%) were associated with a recognised systemic disease or syndrome. Unilateral cataract was identified in 178/342 (52%) of sporadic cases. 79 children (from 54 nuclear families) had a positive family history. Of these 54 families, 45 were recruited for clinical examination and DNA collection. Ten nuclear families were subsequently found to be related, resulting in four larger pedigrees. Thus, 39 families have been studied. The mode of inheritance was autosomal dominant in 30 families, X linked in four, autosomal recessive in two, and uncertain in three. In total, 178 affected family members were examined; of these 8% presented with unilateral cataracts and 43% were diagnosed within the first year of life.

CONCLUSIONS

In the paediatric cataract population examined, approximately half of the patients were diagnosed in the first year of life. More than 18% had a positive family history of cataracts. Of patients with hereditary cataracts 8% presented with unilateral involvement. Identification of the genes that cause paediatric and congenital cataract should help clarify the aetiology of some sporadic and unilateral cataracts.

Visual improvement despite radiologically stable disease after treatment with carboplatin in children with progressive low-grade optic/thalamic gliomas

BACKGROUND

The purpose of this study was to examine the clinical and radiologic response to carboplatin by children with progressive optic/thalamic gliomas.

PATIENTS AND METHODS

Between July 1997 and July 1999, 12 consecutive children were treated with monthly carboplatin for progressive optic/thalamic gliomas.

RESULTS

Five children have completed 12 cycles of carboplatin and five children are currently receiving treatment. Two children had progressive disease noted both clinically and radiologically. Nine children have stable radiologic disease and one child has had a partial radiologic response to chemotherapy. Eight children have had regular visual assessments. Four children (three with stable radiology and one with a partial radiologic response) have had improvement in their vision. Three children with radiologically stable disease have had no change in vision. One child has had deterioration in vision despite radiologically stable disease.

CONCLUSIONS

The results suggest that the clinical response of optic/thalamic gliomas to carboplatin, as measured by visual acuity and visual fields, may be better than predicted by radiologic assessment. These data suggest that a prospective clinical study is warranted of the role of carboplatin in children with progressive optic/thalamic gliomas and visual impairment.

Tension pneumo-orbitus and pneumocephalus induced by a nasal oxygen cannula: report on two paediatric cases

The present paper highlights the potential dangers of misplaced nasopharyngeal oxygen cannulae causing secondary pneumo-orbitus and pneumocephalus in two paediatric patients. While this complication is uncommon, early recognition allows prompt and appropriate intervention, with cessation of nasal oxygen, cannula removal, early investigation with computed tomography (CT) head/orbit scan and orbital or cranial decompression, if required. Early CT imaging identifies medial orbital or paranasal sinus fractures, the presence of sinusitis, associated intracranial air and assessment of the degree of orbital or intracranial tension. Antibiotics are not usually required for this type of clean injury unless pre-existing sinusitis is identified. In both cases, direct orbital decompression was performed with excellent results after identification of marked unilateral tense exophthalmos, delayed pupillary reactions to light and ophthalmopegia.