A bird's eye view on the use of whole exome sequencing in rare congenital ophthalmic diseases.

Phenotypic and genotypic heterogeneity in congenital ocular diseases, especially in anterior segment dysgenesis (ASD), have created challenges for proper diagnosis and classification of diseases. Over the last decade, genomic research has indeed boosted our understanding in the molecular basis of ASD and genes associated with both autosomal dominant and recessive patterns of inheritance have been described with a wide range of expressivity. Here we describe the molecular characterization of a cohort of 162 patients displaying isolated or syndromic congenital ocular dysgenesis. Samples were analyzed with diverse techniques, such as direct sequencing, multiplex ligation-dependent probe amplification, and whole exome sequencing (WES), over 20 years. Our data reiterate the notion that PAX6 alterations are primarily associated with ASD, mostly aniridia, since the majority of the cohort (66.7%) has a pathogenic or likely pathogenic variant in the PAX6 locus. Unexpectedly, a high fraction of positive samples (20.3%) displayed deletions involving the 11p13 locus, either partially/totally involving PAX6 coding region or abolishing its critical regulatory region, underlying its significance. Most importantly, the use of WES has allowed us to both assess variants in known ASD genes (i.e., CYP1B1, ITPR1, MAB21L1, PXDN, and PITX2) and to identify rarer phenotypes (i.e., MIDAS, oculogastrointestinal-neurodevelopmental syndrome and Jacobsen syndrome). Our data clearly suggest that WES allows expanding the analytical portfolio of ocular dysgenesis, both isolated and syndromic, and that is pivotal for the differential diagnosis of those conditions in which there may be phenotypic overlaps and in general in ASD.

Complex balanced intrachromosomal rearrangement involving PITX2 identified as a cause of Axenfeld-Rieger Syndrome.

Axenfeld-Rieger Syndrome (ARS) type 1 is a rare autosomal dominant condition characterized by anterior chamber anomalies, umbilical defects, dental hypoplasia, and craniofacial anomalies, with Meckel's diverticulum in some individuals. Here, we describe a clinically ascertained female of childbearing age with ARS for whom clinical targeted sequencing and deletion/duplication analysis followed by clinical exome and genome sequencing resulted in no pathogenic variants or variants of unknown significance in PITX2 or FOXC1. Advanced bioinformatic analysis of the genome data identified a complex, balanced rearrangement disrupting PITX2. This case is the first reported intrachromosomal rearrangement leading to ARS, illustrating that for patients with compelling clinical phenotypes but negative genomic testing, additional bioinformatic analysis are essential to identify subtle genomic abnormalities in target genes.

Prevalence and prenatal diagnosis of congenital eye anomalies: A population-based study.

OBJECTIVE: To estimate the prevalence and trend of congenital eye anomalies (CEAs) and the rate of prenatal diagnosis over a 10-year period. DESIGN: Retrospective population-based registry study. SETTING: All maternity units in Paris, France, from 2010 to 2020. POPULATION: A cohort of 115 cases of CEA detected among all live births or stillbirths, after 22 weeks of gestation, and terminations of pregnancy. METHODS: The total prevalence of CEAs and prevalence of each specific CEA were calculated using 95% Poisson exact confidence intervals. MAIN OUTCOME MEASURES: The total prevalence of CEAs and the proportion of prenatal diagnosis of CEAs, and their evolution. RESULTS: The prevalence of CEAs was 4.1 (95% CI 3.4-5.0) cases, ranging between 3.1 and 5.7 cases, per 10 000 births. CEAs were prenatally diagnosed in 23.5% of cases. CEAs were bilateral in 51 cases (44.3%), unilateral in 43 cases (37.4%) and missing or unknown in 21 cases (18.3%). Of those with CEAs, 20.9% had genetic anomalies and 53.0% had at least one other extraocular anomaly. When detected prenatally, CEAs were bilateral in 15 cases (55.6%), unilateral in eight cases (29.6%) and missing in the four remaining cases. The prenatal diagnosis rate of CEAs associated with genetic anomalies, CEA cases with at least one other malformation and isolated CEA cases were 29.2%, 26.2% and 13.3%, respectively. CONCLUSIONS: In total, 115 cases of CEAs were observed during the study period, representing a total prevalence of 4.1 cases per 10 000 births. The overall prenatal detection rate of CEAs in our population was 23.5%, which dropped to 13.3% for isolated cases of CEAs.

Axenfeld-Rieger syndrome: more than meets the eye.

BACKGROUND: Axenfeld-Rieger syndrome (ARS) is characterised by typical anterior segment anomalies, with or without systemic features. The discovery of causative genes identified ARS subtypes with distinct phenotypes, but our understanding is incomplete, complicated by the rarity of the condition. METHODS: Genetic and phenotypic characterisation of the largest reported ARS cohort through comprehensive genetic and clinical data analyses. RESULTS: 128 individuals with causative variants in PITX2 or FOXC1, including 81 new cases, were investigated. Ocular anomalies showed significant overlap but with broader variability and earlier onset of glaucoma for FOXC1-related ARS. Systemic anomalies were seen in all individuals with PITX2-related ARS and the majority of those with FOXC1-related ARS. PITX2-related ARS demonstrated typical umbilical anomalies and dental microdontia/hypodontia/oligodontia, along with a novel high rate of Meckel diverticulum. FOXC1-related ARS exhibited characteristic hearing loss and congenital heart defects as well as previously unrecognised phenotypes of dental enamel hypoplasia and/or crowding, a range of skeletal and joint anomalies, hypotonia/early delay and feeding disorders with structural oesophageal anomalies in some. Brain imaging revealed highly penetrant white matter hyperintensities, colpocephaly/ventriculomegaly and frequent arachnoid cysts. The expanded phenotype of FOXC1-related ARS identified here was found to fully overlap features of De Hauwere syndrome. The results were used to generate gene-specific management plans for the two types of ARS. CONCLUSION: Since clinical features of ARS vary significantly based on the affected gene, it is critical that families are provided with a gene-specific diagnosis, PITX2-related ARS or FOXC1-related ARS. De Hauwere syndrome is proposed to be a FOXC1opathy.

New insights into CC2D2A-related Joubert syndrome.

PURPOSE: In this study, we describe the phenotype and genotype of the largest cohort of patients with Joubert syndrome (JS) carrying pathogenic variants on one of the most frequent causative genes, CC2D2A. METHODS: We selected 53 patients with pathogenic variants on CC2D2A, compiled and analysed their clinical, neuroimaging and genetic information and compared it to previous literature. RESULTS: Developmental delay (motor and language) was nearly constant but patients had normal intellectual efficiency in 74% of cases (20/27 patients) and 68% followed mainstream schooling despite learning difficulties. Epilepsy was found in only 13% of cases. Only three patients had kidney cysts, only three had genuine retinal dystrophy and no subject had liver fibrosis or polydactyly. Brain MRIs showed typical signs of JS with rare additional features. Genotype-phenotype correlation findings demonstrate a homozygous truncating variant p.Arg950* linked to a more severe phenotype. CONCLUSION: This study contradicts previous literature stating an association between CC2D2A-related JS and ventriculomegaly. Our study implies that CC2D2A-related JS is linked to positive neurodevelopmental outcome and low rate of other organ defects except for homozygous pathogenic variant p.Arg950*. This information will help modulate patient follow-up and provide families with accurate genetic counselling.

Non-vascular intracranial lesions in three children with PHACE association.

PHACE (posterior fossa malformations, hemangiomas, arterial anomalies, cardiac anomalies, eye anomalies) association has many recognized clinical features. A link between PHACE and non-vascular intracranial lesions has not been well-described. We report three pediatric patients with PHACE and non-vascular intracranial lesions.

Duplication of the Lacrimal Sac With Three Canaliculi.

Complex congenital lacrimal drainage anomalies are known to be associated with several syndromes and present unique surgical challenges. Duplication of human body structures is uncommon and has been reported in the uterus (uterine didelphys), ureter (duplex ureter), duodenum, transverse colon, and nose. Lacrimal drainage anomalies have been reported in proboscis lateralis. To the best of the authors' knowledge, there are no prior reports on duplication of the lacrimal sac. The present case reports a complex congenital nasolacrimal duct obstruction that was associated with duplication of the lacrimal sac and the presence of 3 canaliculi.

Cleft Lip With Ankyloblepharon Filiforme Adnatum: A Case Report.

Ankyloblepharon filiforme adnatum (AFA) is a rare, benign congenital anomaly. Notably, it is characterized by the adhesion of the ciliary edges of the upper and lower eyelids at the trabecular line. AFA is usually a solitary malformation of sporadic occurrence; however, it can occur in conjunction with other congenital diseases. Herein, we report a case of cleft lip with AFA. A patient was referred to the ophthalmology department of our hospital. The ophthalmic diagnosis was AFA in both the eyes. The left eye was observed to have a fibrous adhesion in the center, and she underwent surgery to excise the fibrous adhesion of tissue with scissors. The right eye was observed to have a fibrous adhesion in the external canthus and was excised during lip plasty. After surgery, her eyes were able to fully open, and no other apparent disease was diagnosed. AFA is thought to be caused by an ectodermal-derived developmental abnormality. Notably, cases of AFA with a cleft lip are rare. Diagnosis and surgery should be performed promptly to minimize any risk of amblyopia and for the early detection of congenital diseases, including glaucoma.

PREVALENCE OF OCULAR ABNORMALITIES AND NORMAL DIAGNOSTIC PARAMETERS IN TWO GROUPS OF PANAMANIAN GOLDEN FROGS (ATELOPUS ZETEKI).

Panamanian golden frog (PGF) (Atelopus zeteki) is a critically endangered species. The Maryland Zoo in Baltimore houses two groups of PGF originating from distinct geographic locations as an assurance colony, with the goal of upholding genetics for future release of individuals back to their native environment. The purpose of this cross-sectional study was to characterize the prevalence of ocular abnormalities in these two zoo-housed populations of PGF as well as to establish normal parameters for selected diagnostic tests in these groups. Twenty-five females and 25 males were randomly selected from each group (100 PGF; 200 eyes in total) to undergo ocular examination using slit lamp biomicroscopy and direct ophthalmoscopy. Endodontic absorbent paper point test (EAPPT) and intraocular pressure (IOP) and Rose Bengal stain diagnostic tests were also performed. Reference ranges for tear production (EAPPT, 0.5-3 mm/min) and IOP (14-26 mmHg) were calculated in the nondiseased PGF eyes (n = 160 eyes). Rose Bengal stain uptake was negative on all eyes. In total, 40 eyes of 30 PGF were found to have some form of ocular abnormality (28% of PGF, 20% of eyes). The most frequently observed ocular abnormalities were cataract (9% of PGF, 6% of eyes) and keratitis (nonlipid keratopathy; 10% of PGF, 5.5% of eyes). There was no significant difference in overall ocular abnormality prevalence between the two groups studied (P = 0.37) or between the sexes (P = 0.76). The median age of an eye with cataract and keratitis (nonlipid keratopathy) was 10.35 and 7.7 yr, respectively. Ocular abnormalities are common in these two populations of PGF. Documentation of these ocular abnormalities and establishment of diagnostic reference ranges have not previously been published and may be important for maintaining the health of this endangered species.

Ocular manifestations and treatment progress of Crouzon syndrome.

PURPOSE: Crouzon syndrome is a congenital genetic disease caused by mutations of the FGFR2 gene on chromosome 10. It is usually inherited in an autosomal dominant pattern and is one of the most common types of craniosynostosis syndromes. This article focuses on the ophthalmology-related aspects of Crouzon syndrome in order to help diagnose and develop personalized treatment plans. METHODS: A combined systematic search of PubMed electronic database by using Boolean operators AND and OR was conducted, choosing the following keywords: "Crouzon", "craniosynostosis", " eye ", " oculus ", " ocular ", " ophthalmic ", " ophthalmologic ", " ophthalmology ", " globe ", " orbit ", " exophthalmos ", " exorbitism ", " keratopathy ", " visual " etc. After the initial screening of these articles, repetitive literatures were excluded. RESULTS: 47 articles were selected. This article introduces the ocular manifestations, possible pathogenesis and treatment progress in Crouzon syndrome. CONCLUSIONS: The incidence of ocular abnormalities in Crouzon syndrome is very high, such as shallow orbits, exophthalmos, hypertelorism, exposure keratopathy, strabismus, optic neuropathy, ametropia, glaucoma, etc. The pathogenesis of these ocular abnormalities is related to orbital deformities. Most of the treatments are aimed at compensating the abnormal anatomic structure at present.

Chromosome 6p25 deletion syndrome: A case report and review of ophthalmic features.

The 6p25 deletion syndrome is a rare genetic disorder characterized by a wide spectrum of congenital anomalies. Ophthalmic abnormalities appear to be highly associated with the syndrome, although this relationship has not been well characterized to date. We conducted a systematic literature review to highlight the ocular features in patients with this deletion syndrome and describe a 7-month-old female who has a 6.07 MB 6p25.1p25.3 deletion and a 4.25 MB 17q25.3 duplication. Our patient presented with multiple congenital anomalies, including macrocephaly, frontal bossing, low set ears, tent-shaped mouth, saddle nose, flat midface, and hearing impairment. Her ophthalmic features included proptosis, down-slanting palpebral fissures, hypertelorism, nystagmus, bilateral posterior embryotoxon, and decentered and abnormally shaped pupils. A systematic review of the published cases with sufficient clinical eye descriptions included 63 cases with a confirmed 6p25 deletion. The most common eye findings observed were posterior embryotoxon, iris hypoplasia, corectopia, cornea opacity, and glaucoma.

PHACES-like syndrome with TMEM260 compound heterozygous variants.

PHACES syndrome is a multiple congenital disorder with unknown etiology that is characterized by Posterior fossa anomalies, Hemangioma, Arterial lesions, Cardiac abnormalities/coarctation of the aorta, Eye anomalies, and Sternal cleft. Compound heterozygous or homozygous TMEM260 variants cause structural heart defects and renal anomalies syndrome (SHDRA). We describe a 10-year-old male patient with a PHACES-like syndrome and TMEM260 compound heterozygous variants who demonstrated overlapping phenotypes between the two syndromes. He presented with truncus arteriosus, supraumbilical raphe, ophthalmological abnormality, vertebral abnormality, borderline intellectual disability, and hearing loss. He had normal serum creatinine. In proband exome sequencing, compound heterozygous TMEM260 variants (NM_017799.4 c.1617delG p.(Trp539Cysfs*9)/c.1858C > T p.(Gln620*)) were identified. Twelve patients have been reported with TMEM260-related SHDRA: 10 had truncus arteriosus and 6 had renal failure. One previously reported patient had facial port wine nevus and another patient had supraumbilical raphe, which are the cardinal signs for PHACES syndrome. TMEM260-related SHDRA could share overlapping clinical features with PHACES syndrome. This report expands the phenotypic spectrum of a TMEM260-related disorder.

Oculoauriculofrontonasal syndrome: Refining the phenotype through a new case series and literature review.

The oculoauriculofrontonasal syndrome (OAFNS) is a rare condition, with unknown etiology, characterized by the association of frontonasal dysplasia (FND) and oculoauriculovertebral spectrum (OAVS). Main clinical findings include widely spaced eyes, epibulbar dermoid, broad nose, mandibular hypoplasia, and preauricular tags. Here, we describe a case series of 32 Brazilian individuals with OAFNS and review the literature ascertaining individuals presenting phenotypes compatible with the diagnosis of OAFNS, aiming to refine the phenotype. This series emphasizes the phenotypic variability of the OAFNS and highlights the occurrence of rare craniofacial clefts as a part of the phenotype. The ectopic nasal bone, a hallmark of OAFNS, was frequent in our series, reinforcing the clinical diagnosis. The absence of recurrence, consanguinity, chromosomal, and genetic abnormalities reinforces the hypothesis of a nontraditional inheritance model. The phenotypic refinement provided by this series contributes to an investigation regarding the etiology of OAFNS.

SOX2 pathogenic variants with normal eyes: Expanding the phenotypic spectrum.

SOX2 pathogenic variants, though rare, constitute the most commonly known genetic cause of clinical anophthalmia and microphthalmia. However, patients without major ocular malformation, but with multi-system developmental disorders, have been reported, suggesting that the range of clinical phenotypes is broader than previously appreciated. We detail two patients with bilateral structurally normal eyes along with 11 other previously published patients. Our findings suggest that there is no obvious phenotypic or genotypic pattern that may help set apart patients with normal eyes. Our patients provide further evidence for broadening the phenotypic spectrum of SOX2 mutations and re-appraising the designation of SOX2 disorder as an anophthalmia/microphthalmia syndrome. We emphasize the importance of considering SOX2 pathogenic variants in the differential diagnoses of individuals with normal eyes, who may have varying combinations of features such as developmental delay, urogenital abnormalities, gastro-intestinal anomalies, pituitary dysfunction, midline structural anomalies, and complex movement disorders, seizures or other neurological issues.

TOPORS as a novel causal gene for Joubert syndrome.

Joubert syndrome (JBTS) is a Mendelian disorder of the primary cilium defined by the clinical triad of hypotonia, developmental delay, and a distinct cerebellar malformation called the molar tooth sign. JBTS is inherited in an autosomal recessive, autosomal dominant, or X-linked recessive manner. Though over 40 genes have been identified as causal for JBTS, molecular diagnosis is not made in 30%-40% of individuals who meet clinical criteria. TOPORS encodes topoisomerase I-binding arginine/serine-rich protein, and homozygosity for a TOPORS missense variant (c.29C > A; p.(Pro10Gln)) was identified in individuals with the ciliopathy oral-facial-digital syndrome in two families of Dominican descent. Here, we report an additional proband of Dominican ancestry with JBTS found by exome sequencing to be homozygous for the identical p.(Pro10Gln) TOPORS missense variant. Query of the Mount Sinai BioMe biobank, which includes 1880 individuals of Dominican ancestry, supports a high carrier frequency of the TOPORS p.(Pro10Gln) variant in individuals of Dominican descent. Our data nominates TOPORS as a novel causal gene for JBTS and suggests that TOPORS variants should be considered in the differential of ciliopathy-spectrum disease in individuals of Dominican ancestry.

Sirolimus for diffuse intestinal infantile hemangioma with PHACE features: systematic review.

BACKGROUND: We report a 3-month-old female with cardiovascular anomalies and diffuse intestinal infantile hemangioma (IIH) of the small bowel suggesting possible diagnosis of PHACE syndrome (posterior fossa anomalies, hemangioma, arterial lesions, cardiac abnormalities/coarctation of the aorta, eye anomalies). The GI symptoms persisted under treatment with propranolol, whereas the addition of sirolimus led to regression of the IIH. METHODS: A systematic review was conducted using PubMed, EMBASE, and Ovid MEDLINE databases between 1982 and 2021. RESULTS: A total of 4933 articles were identified; 24 articles met inclusion criteria with 46 IIH cases. The most common GI presentations were unspecified GI bleed (40%) and anemia (38%). The most common treatments were corticosteroids (63%), surgical resection (32.6%), and propranolol (28%). Available outcomes were primarily bleeding arrest (84%). Nine cases (19.5%) were diagnosed with definite PHACE, 5 (11%) with possible PHACE, and 32 (69.5%) no PHACE. Our case presented with symptoms most consistent with those of possible PHACE and definite PHACE. No cases in this review underwent treatment with sirolimus. CONCLUSIONS: This is the first reported case of successful treatment of IIH with sirolimus. Our case, along with other patients who present with IIH and PHACE features, suggests consideration of IIH as a diagnostic criterion for PHACE syndrome. IMPACT: This is the first reported case in which sirolimus showed regression of an intestinal infantile hemangioma. This study serves to demonstrate the presentation, treatment, outcomes of intestinal infantile hemangioma, and correlation with PHACE. The potential correlation between intestinal infantile hemangioma and PHACE deserves more study in consideration of intestinal infantile hemangioma as a diagnostic criterion of PHACE.

Variants of BEST1 and CRYBB2 cause a complex ocular phenotype comprising microphthalmia, microcornea, cataract, and vitelliform macular dystrophy: case report.

BACKGROUND: Best vitelliform macular dystrophy (BVMD), caused by pathogenic variants of the BEST1 gene, has not been reported in association with cataracts and ocular malformations. We reported a case with a complex ocular phenotype comprising microphthalmia, microcornea, cataract, and vitelliform macular dystrophy. CASE PRESENTATION: A six-year-old girl manifested photophobia and a poor visual behavior. A thorough ophthalmic examination revealed the patient to have bilateral microphthalmia, microcornea, congenital cataract, and Best vitelliform macular dystrophy (BVMD). Whole exome sequencing (WES) identified one variant in the BEST1 and one variant in CRYBB2 genes: c.218 T > G p.(Ile73Arg) and c.479G > C p.(Arg160Pro). The first variant was inherited from the proband's father, who was diagnosed with subclinical BVMD, while the second was a de novo variant. A minigene assay showed that c.218 T > G in BEST1 did not affect pre-mRNA splicing. CONCLUSIONS: This case suggests that the complex ocular phenotype comprising BVMD and congenital cataract with microphthalmia cannot be explained by variation in one gene but is caused by variants in BEST1 and CRYBB2. This case highlights the importance of general clinical evaluation and comprehensive genetic testing for diagnosing complex eye diseases.

A unique case of bilateral nanophthalmos and pigmentary retinal abnormality with unilateral angle closure glaucoma and optic disc pit.

BACKGROUND: Microophthalmos or 'dwarf eye' is characterized by an axial length 2 standard deviation less than age-matched controls. It is classified into nanophthalmos, relative anterior microphthalmos, and posterior microphthalmos based on the anterior segment: posterior segment ratio. Nanophthalmos can occur in association with optic disc drusen, foveoschisis, and retinitis pigmentosa, as an autosomal recessive syndrome linked to mutations in the MFRP gene. We report a case of bilateral nanophthalmos and pigmentary retinopathy with angle closure glaucoma and optic disc pit in one eye. We believe this to be the first case presenting with optic disc pit in association with nanophthalmos. CASE PRESENTATION: A 56-year-old female presented with bilateral small eyes, high hypermetropia, shallow anterior chamber depth, increased lens thickness, mid-peripheral retinal flecks, and macular edema. She also had high intraocular pressure in the right eye, with a disc cupping of 0.9 with an Optic disc pit. The macular edema in the right eye was found to occur in association with the Optic disc pit, whereas, in the left eye, it was associated with intra-retinal hemorrhages and diagnosed as macular branch retinal vein occlusion secondary to hypertension. She was started on anti-glaucoma medications in both eyes and planned for Anti-VEGF injection in the left eye. CONCLUSION: This case report is unique as it reports an association of Nanophthalmos with Optic Disc pit, with an associated angle closure glaucoma in the same eye, an association which has never been previously reported in the literature.

Cardiac anomalies in Axenfeld-Rieger syndrome.

Axenfeld-Rieger syndrome is a rare multi-system disorder associated with cardiac anomalies. All patients with a diagnosis of Axenfeld-Rieger syndrome were identified from our electronic medical record. Chart review was performed to document the presence and types of CHD. Out of 58 patients, 14 (24.1%) had CHD and a wide variety of cardiac lesions were identified.

Bilateral Intraorbital Opticmeningoceles in Joubert Syndrome.

Congenital opticmeningoceles was the term coined to describe large pseudocystic lesions of the intraorbital segment of the optic nerve. This extremely rare congenital anomaly was reported unilaterally only in nonsyndromic patients with fully developed eyes. The authors describe here a 10-month-old girl with a previous diagnosis of Joubert syndrome who presented with the same type of optic nerve malformation in OU. Molecular genetic analysis disclosed a pathogenic variant of the TMEM67 gene which is associated with various types of ciliopathies.