Bilateral Peters' anomaly, aniridia and Wilms tumour (WAGR syndrome) in monozygotic twins

AIM

This study reports the bilateral association of Peters' anomaly and congenital aniridia in monozygotic twins subsequently diagnosed with Wilms tumour (WAGR syndrome).

METHODS

Two monozygotic female twins were referred at age 2 months with bilateral corneal opacity. A diagnosis of Peters' anomaly associated to aniridia was made in both eyes of both twins. Physical examination and ultrasonography were carried out at 12 months of age to explore the possibility of WAGR-related anomalies, specifically Wilms tumour. DNA were isolated and subjected to whole exome sequencing.

RESULTS

Peters' anomaly associated to aniridia in both eyes as well as bilateral Wilms tumour in both children were diagnosed. Exome analyses showed a large heterozygous deletion encompassing 6 648 473 bp in chromosome 11p13, using Integrative Genomics Viewer and AnnotSV software.

CONCLUSION

WAGR syndrome is a rare contiguous gene deletion syndrome with a greater risk of developing Wilms tumour associated with Peters' anomaly and congenital aniridia. However, co-occurrence of both anomalies was rarely reported in twins, and never in both eyes of monozygotic twins. Here, we report the bilateral association of Peters' anomaly and congenital aniridia in monozygotic twins with WAGR syndrome.

Transconjunctival XEN45 implantation for secondary open-angle glaucoma management in a pediatric patient with WAGR syndrome

Purpose

To report a case of XEN45 gel stent implantation in a pediatric patient with WAGR syndrome as a successful surgical intervention in the management of multifactorial secondary open-angle glaucoma.

Observations

A 6-year-old female with a history of WAGR syndrome, bilateral congenital aniridia, pseudophakia OD and glaucoma OD, was referred for a XEN45 gel stent OD. IOP was persistently elevated at 24 mm Hg despite two glaucoma medications. Implantation of the XEN45 gel stent was performed using a transconjunctival ab externo approach. There were no significant intra-or-postoperative adverse events associated with the stent. The patient achieved good IOP-lowering control without glaucoma medications across the 18-month follow-up period.

Conclusions

A XEN45 stent through a transconjunctival ab externo approach may be an effective surgical intervention in pediatric patients with secondary open-angle glaucoma associated with aniridia and aphakia.

Complex Chromosomal Rearrangement Involving Chromosomes 10 and 11, Accompanied by Two Adjacent 11p14.1p13 and 11p13p12 Deletions, Identified in a Patient with WAGR Syndrome

Three years ago, our patient, at that time a 16-month-old boy, was discovered to have bilateral kidney lesions with a giant tumor in the right kidney. Chemotherapy and bilateral nephron-sparing surgery (NSS) for Wilms tumor with nephroblastomatosis was carried out. The patient also had eye affection, including glaucoma, eye enlargement, megalocornea, severe corneal swelling and opacity, complete aniridia, and nystagmus. The diagnosis of WAGR syndrome was suspected. De novo complex chromosomal rearrangement with balanced translocation t(10,11)(p15;p13) and a pericentric inversion inv(11)(p13q12), accompanied by two adjacent 11p14.1p13 and 11p13p12 deletions, were identified. Deletions are raised through the complex molecular mechanism of two subsequent rearrangements affecting chromosomes 11 and 10. WAGR syndrome diagnosis was clinically and molecularly confirmed, highlighting the necessity of comprehensive genetic testing in patients with congenital aniridia and/or WAGR syndrome.

Epidemiology of PAX6 Gene Pathogenic Variants and Expected Prevalence of PAX6-Associated Congenital Aniridia across the Russian Federation: A Nationwide Study

This study investigates the distribution of PAX6-associated congenital aniridia (AN) and WAGR syndrome across Russian Federation (RF) districts while characterizing PAX6 gene variants. We contribute novel PAX6 pathogenic variants and 11p13 chromosome region rearrangements to international databases based on a cohort of 379 AN patients (295 families, 295 probands) in Russia. We detail 100 newly characterized families (129 patients) recruited from clinical practice and specialized screening studies. Our methodology involves multiplex ligase-dependent probe amplification (MLPA) analysis of the 11p13 chromosome, PAX6 gene Sanger sequencing, and karyotype analysis. We report novel findings on PAX6 gene variations, including 67 intragenic PAX6 variants and 33 chromosome deletions in the 100 newly characterized families. Our expanded sample of 295 AN families with 379 patients reveals a consistent global PAX6 variant spectrum, including CNVs (copy number variants) of the 11p13 chromosome (31%), complex rearrangements (1.4%), nonsense (25%), frameshift (18%), and splicing variants (15%). No genetic cause of AN is defined in 10 patients. The distribution of patients across the Russian Federation varies, likely due to sample completeness. This study offers the first AN epidemiological data for the RF, providing a comprehensive PAX6 variants spectrum. Based on earlier assessment of AN prevalence in the RF (1:98,943) we have revealed unexamined patients ranging from 55% to 87%, that emphases the need for increased awareness and comprehensive diagnostics in AN patient care in Russia.

Visual Acuity in Aniridia and WAGR Syndrome

Purpose

Our purpose was to evaluate visual acuity in aniridia subjects and the more severely affected phenotype in WAGR syndrome subjects, and to assess potential impact on visual function.

Materials and Methods

This was a retrospective comparative study of 25 aniridia subjects with nonsense mutations of PAX6 (50 eyes) and 25 WAGR syndrome subjects with large deletion mutations involving PAX6 (50 eyes). Aniridia subjects were age- and gender-matched with WAGR syndrome subjects in the Coordination of Rare Diseases at Sanford (CoRDS) database. Best-corrected ETDRS visual acuity measurements were converted to LogMAR visual acuity values, which were used to perform statistical analyses.

Results

The age and gender distribution of the subjects was not statistically significantly different. The mean LogMAR values in aniridia and WAGR syndrome subjects were 0.95±0.53 and 1.51±0.99, respectively (P<0.001). In the better-seeing eye, mean LogMAR values were 0.78±0.15 in aniridia subjects and 1.40±0.88 in WAGR syndrome subjects (P=0.001). The mean LogMAR values for the better-seeing eye corresponded to Snellen visual acuity of 20/125 in aniridia subjects and 20/500 in WAGR syndrome subjects. This average visual acuity was worse than the threshold for profound visual impairment (WHO criteria) and legal blindness (AAO criteria) in WAGR syndrome but not in aniridia subjects. In analysis of both eyes, the visual efficiency was 34% in aniridia subjects and 2% in WAGR syndrome subjects.

Conclusion

Visual acuity was significantly worse in WAGR subjects with multi-gene deletion mutations compared with aniridia subjects with nonsense mutations, which corresponded to differences in standard visual function thresholds. Our results suggest that visual acuity may indicate severity of ocular involvement and variability of phenotype in aniridia and WAGR syndrome.

Unusual Presentation in WAGR Syndrome: Expanding the Phenotypic and Genotypic Spectrum of the Diseases

The deletion of chromosome 11p13 involving the WT1 and PAX6 genes has been shown to cause WAGR syndrome (OMIM #194072), a rare genetic disorder that features Wilms’ tumor, aniridia, genitourinary anomalies, as well as mental retardation. In this study, we expand the genotypic and phenotypic spectrum of WAGR syndrome by reporting on six patients from six unrelated families with different de novo deletions located on chromosome 11p13. Very rare phenotypes of lens automated absorption and lens thinning were detected in four of the six patients. We assessed the involvement of the ARL14EP gene in patients with and without severe lens abnormalities and found that its deletion may worsen the lens abnormalities in these patients.

Characterization of Associated Nonclassical Phenotypes in Patients with Deletion in the WAGR Region Identified by Chromosomal Microarray: New Insights and Literature Review

WAGR syndrome (Wilms' tumor, aniridia, genitourinary changes, and intellectual disability) is a contiguous gene deletion syndrome characterized by the joint deletion of PAX6 and WT1 genes, located in the short arm of chromosome 11. However, most deletions include other genes, leading to multiple associated phenotypes. Therefore, understanding how genes deleted together can contribute to other clinical phenotypes is still considered a challenge. In order to establish genotype-phenotype correlation in patients with interstitial deletions of the short arm of chromosome 11, we selected 17 patients with deletions identified by chromosomal microarray analysis: 4 new subjects and 13 subjects previously described in the literature with detailed clinical data. Through the analysis of deleted regions and the phenotypic changes, it was possible to suggest the contribution of specific genes to several nonclassical phenotypes, contributing to the accuracy of clinical characterization of the syndrome and emphasizing the broad phenotypic spectrum found in the patients. This study reports the first patient with a PAX6 partial deletion who does not present any eye anomaly thus opening a new set of questions about the functional activity of PAX6.

[National protocol for diagnosis and care of congenital aniridia: Summary for the attending physician]

Congenital aniridia is a rare panocular disease defined by a national diagnostic and care protocol (PNDS) validated by the HAS. In most cases, it is due to an abnormality in the PAX6 gene, located at 11p13. Aniridia is a potentially blinding autosomal dominant disease with high penetrance. The prevalence varies from 1/40,000 births to 1/96,000 births. Approximately one third of cases are sporadic. Ocular involvement includes complete or partial absence of iris tissue, corneal opacification with neovascularization, glaucoma, cataract, foveal hypoplasia, optic disc hypoplasia and ptosis. These ocular disorders coexist to varying degrees and progress with age. Congenital aniridia manifests in the first months of life as nystagmus, visual impairment and photophobia. A syndromic form such as WAGR syndrome, WAGRO syndrome (due to the risk of renal Wilms tumor) or Gillespie syndrome (cerebellar ataxia) must be ruled out. Systemic associations may include diabetes, due to expression of the PAX6 gene in the pancreas, as well as other extraocular manifestations. Initial assessment is best carried out in a referral center specialized in rare ophthalmologic diseases, with annual follow-up. The management of progressive ocular involvement must be both proactive and responsive, with medical and surgical management. Visual impairment and photophobia result in disability, leading to difficulties in mobility, movement, communication, learning, fine motor skills, and autonomy, with consequences in personal, school, professional, socio-cultural and athletic life. Medico-socio-educational care involves a multidisciplinary team. Disability rehabilitation must be implemented to prevent and limit situations of handicap in activities of daily living, relying on the Commission for the Rights and Autonomy of People with Disabilities (CDAPH) within the Departmental House of People with Disabilities (MDPH). The general practitioner coordinates multidisciplinary medical and paramedical care.

Neuropsychological and neurophysiological features of WAGR syndrome: Detailed comprehensive evaluation of a patient with severe intellectual disability and autism spectrum disorder

BACKGROUND

Wilms' tumor, aniridia, genitourinary anomalies, and mental retardation (WAGR) syndrome is a contiguous gene deletion syndrome caused by a de novo deletion including the 11p13 region. Although autism spectrum disorder (ASD) is frequently observed in patients with WAGR syndrome, few reports have comprehensively described its characteristics. We herein present the detailed neuropsychological and neurophysiological findings of a patient with WAGR syndrome complicated with severe psychomotor developmental delay and ASD.

CASE PRESENTATION

The patient is presently a 6-year-old boy. Microarray analysis revealed a 7.1 Mb loss at 11p14.3-p13 and a 9.3 Mb loss at 11p13-p12, which encompassed the PAX6, WT1, and PRRG4 genes. His behavioral features were characteristic even among the ASD population: severe hypoesthesia to touch, pain, and temperature in addition to remarkable sensory seeking posing a high risk of serious accident. Sensory Profile analysis objectively identified a strong preference for sensory stimulation. Furthermore, his somatosensory evoked potential (SSEP) showed a mild delay in central conduction time, suggesting partial brain stem dysfunction-induced hypoalgesia.

DISCUSSION

This first attempt to characterize sensory dysfunction using Sensory Profile and SSEP in WAGR syndrome may contribute to understanding its neuropsychological features and improve the quality of rehabilitation and socioeducational support in affected children.

Genetics and epidemiology of aniridia: Updated guidelines for genetic study

Aniridia is a panocular disease characterized by iris hypoplasia, accompanied by other ocular manifestations, with a high clinical variability and overlapping with different abnormalities of the anterior and posterior segment. This review focuses on the genetic features of this autosomal dominant pathology, which is caused by the haploinsufficiency of the PAX6 gene. Mutations causing premature stop codons are the most frequent among the wider mutational spectrum of PAX6, with more than 600 different mutations identified so far. Recent advances in next-generation sequencing (NGS) have increased the diagnostic yield in aniridia and contributed to elucidate new etiopathogenic mechanisms leading to PAX6 haploinsufficiency. Here, we also update good practices and recommendations to improve genetic testing and clinical management of aniridia using more cost-effective NGS analysis. Those new approaches also allow studying simultaneously both structural variants and point-mutations in PAX6 as well as other genes for differential diagnosis, simultaneously. Some patients with atypical phenotypes might present mutations in FOXC1 and PITX2, both genes causing a wide spectrum of anterior segment dysgenesis, or in ITPR1, which is responsible for a distinctive form of circumpupillary iris aplasia present in Gillespie syndrome, or other mutations in minor genes. Since aniridia can also associate extraocular anomalies, as it occurs in carriers of PAX6 and WT1 microdeletions leading to WAGR syndrome, genetic studies are crucial to assure a correct diagnosis and clinical management, besides allowing prenatal and preimplantational genetic testing in families.

Sequences of COVID-19 in a child with WAGR syndrome: A case report

Introduction

and importance: WAGR syndrome is a rare genetic disorder consist of Wilms tumor, Aniridia, Genitourinary abnormalities, and Intellectual disability. During the enduring COVID-19 pandemic, it has become extremely important to document the properties of SARS-CoV-2 and its interactions with other diseases. Herein, we present the first case of Syrian child with WAGR syndrome that has been affected by COVID-19.

Case presentation

a 17-month-old boy was diagnosed with WAGR syndrome. During the follow-up, he developed rhinorrhea, cough, and moderate dyspnea with no fever. Computed tomography scan was normal and polymerase chain reaction test was positive. The child started an oxygen therapy with broad-spectrum antibiotics based on laboratory findings. His vital signs and laboratory values improved gradually without any further complications.

Discussion

COVID-19 has a special interest regarding its course in children. Although the clinical presentation varies, the current data reveal a better prognosis in children.

Conclusion

SARS-CoV-2 infection may result in non-specific symptoms and normal CT scan findings in children with WAGR syndrome. The accurate diagnosis, effective isolation and monitoring of the child, and successful management can improve the prognosis and shorten the infection period.

Genetics and epidemiology of aniridia: Updated guidelines for genetic study

Aniridia is a panocular disease characterized by iris hypoplasia, accompanied by other ocular manifestations, with a high clinical variability and overlapping with different abnormalities of the anterior and posterior segment. This review focuses on the genetic features of this autosomal dominant pathology, which is caused by the haploinsufficiency of the PAX6 gene. Mutations causing premature stop codons are the most frequent among the wider mutational spectrum of PAX6, with more than 600 different mutations identified so far. Recent advances in next-generation sequencing (NGS) have increased the diagnostic yield in aniridia and contributed to elucidate new etiopathogenic mechanisms leading to PAX6 haploinsufficiency. Here, we also update good practices and recommendations to improve genetic testing and clinical management of aniridia using more cost-effective NGS analysis. Those new approaches also allow studying simultaneously both structural variants and point-mutations in PAX6 as well as other genes for differential diagnosis, simultaneously. Some patients with atypical phenotypes might present mutations in FOXC1 and PITX2, both genes causing a wide spectrum of anterior segment dysgenesis, or in ITPR1, which is responsible for a distinctive form of circumpupillary iris aplasia present in Gillespie syndrome, or other mutations in minor genes. Since aniridia can also associate extraocular anomalies, as it occurs in carriers of PAX6 and WT1 microdeletions leading to WAGR syndrome, genetic studies are crucial to assure a correct diagnosis and clinical management, besides allowing prenatal and preimplantational genetic testing in families.

Identification of a 6-month-old baby with a combination of WAGR and Potocki-Shaffer contiguous deletion syndromes by SNP array testing

WAGR 11p13 deletion syndrome is associated with abnormalities including (W) ilms tumor, (A) niridia, (G) enitourinary abnormalities, and growth and mental (R) etardation (WAGR). Potocki–Schaffer syndrome is a contiguous gene syndrome associated with deletions in 11p11.2, principal features of which are multiple exostoses, parietal foramina development delay, mental retardation, and facial dysmorphism. In some cases, males may have enlarged anterior fontanels and genital abnormalities. Each of these syndromes is very rare. Here we report a patient with both WAGR and Potocki–Shaffer syndromes who presented with aniridia, nystagmus, macular dysplasia, enlarged anterior fontanel, mental retardation, ptosis, low-set ears, micrognathia, and atrial septal defect at 6 months old. SNP array revealed a large (26.25 Mb)deletion: arr[hg19]11p15.1p11.2(18742043–44991839)× 1. Genetic testing allowed for diagnosis of this patient at a very young age. In addition to the postnatal phenotype of the patient, we found one prenatal symptom of these syndromes is oligohydramnios, which when present might indicate advanced prenatal diagnosis. This made the possibility of prenatal diagnosis for these syndromes.

Pediatric case report]

WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies and mental retardation) is an uncommon genetic disorder due to the deletion of the 11p13 region that contains the WT1 and PAX6 genes. It involves a distinctive combination of clinical conditions, with aniridia and Wilms tumor being the most notable. We present a 17-month-old infant with microcephaly, ocular alterations (buphthalmos, leukocoria, bilateral aniridia), scrotal hypoplasia, undescended testes and neurodevelopmental delay who underwent multiplex ligation-dependent probe amplification study for WT1, showing haploinsufficiency in the probes that hybridize to the 11p13 region, compatible with an heterozygous deletion of the gene. Wilms tumor was later diagnosed. WAGR syndrome is infrequent; its report in Latin America is low. It is important to disseminate its clinical characteristics, emphasizing an interdisciplinary management focused on the early identification of both the syndrome and its possible complications.

A nonsense PAX6 mutation in a family with congenital aniridia

Congenital aniridia is a rare ocular malformation that presents with severe hypoplasia of the iris and various ocular manifestations. Most cases of congenital aniridia are known to be related to mutations in the paired box gene-6 (PAX6), which is an essential gene in eye development. Herein, we report a familial case of autosomal dominant congenital aniridia with four affected members in 3 consecutive generations and describe the detailed ophthalmologic findings for one of these members. As expected, mutational analysis revealed a nonsense mutation (p.Ser122^*) in the PAX6 gene. Thus, our findings reiterate the importance of PAX6 mutations in congenital aniridia.

Dysgerminoma developing from an ectopic ovary in a patient with WAGR syndrome: A case report

WAGR syndrome is caused by an 11p13 deletion and includes Wilms' tumor, aniridia, genitourinary anomalies and mental retardation. We encountered a case of a dysgerminoma originating in an ectopic ovary in a woman with WAGR syndrome. Our patient was a 24-year-old nulliparous woman who was diagnosed with WAGR syndrome. The patient had undergone left nephrectomy for a Wilms' tumor and postoperative chemotherapy at the age of 7 months. She also had a history of glaucoma surgery in both eyes, and was followed up at the Department of Pediatrics for diabetes mellitus, hypertension, liver dysfunction and hyperuricemia. The patient was investigated for oliguria and had elevated levels of blood urea nitrogen (45 mg/dl) and creatinine (5.4 mg/dl); she was admitted to the hospital with acute renal failure and a computed tomography scan revealed a pelvic tumor with a long axis of 10 cm that was obstructing the right ureter. Following insertion of a ureteral stent, the tumor was removed. The tumor had developed in the retroperitoneal space independent of the ovaries. The right adnexa were normal. The tumor was histopathologically diagnosed as dysgerminoma. Follicles were found in part of the tumor; it was thus hypothesized that the tumor developed from an ectopic ovary. The patient was administered etoposide after surgery, and has been recurrence-free for 4 years since treatment.

A case of WAGR syndrome in association with developmental glaucoma requiring bilateral Baerveldt glaucoma implants and subsequent tube repositioning

Glaucoma drainage device implantation is efficacious for the treatment of pediatric glaucoma patients when multiple angle surgeries fail. However, tube touching of the corneal endothelium is one of the major postoperative complications to deal with. A 15-month-old male patient with Wilms' tumor, aniridia, genitourinary anomalies, and mental retardation (WAGR) syndrome was diagnosed with bilateral developmental glaucoma. He underwent Baerveldt glaucoma implant (BGI) surgeries in both eyes after multiple failed trabeculotomies. The tube in his right eye was touching the cornea 15 months after BGI surgery. To avoid corneal endothelium damage, BGI tube repositioning with scleral fixation was performed without serious complications. The bilateral BGI surgeries achieved successful intraocular pressure reduction for over 2 years and tube repositioning with scleral fixation of BGI tube was successful for BGI tube malposition. Although careful attention to intraocular pressure and tube malposition is essential after glaucoma drainage device implantation, especially in pediatric cases, BGI surgery is effective in the management of developmental glaucoma following unsuccessful angle surgeries.

Association of brain-derived neurotrophic factor (BDNF) haploinsufficiency with lower adaptive behaviour and reduced cognitive functioning in WAGR/11p13 deletion syndrome

In animal studies, brain-derived neurotrophic factor (BDNF) is an important regulator of central nervous system development and synaptic plasticity. WAGR (Wilms tumour, Aniridia, Genitourinary anomalies, and mental Retardation) syndrome is caused by 11p13 deletions of variable size near the BDNF locus and can serve as a model for studying human BDNF haploinsufficiency (+/-). We hypothesized that BDNF+/- would be associated with more severe cognitive impairment in subjects with WAGR syndrome. Twenty-eight subjects with WAGR syndrome (6-28 years), 12 subjects with isolated aniridia due to PAX6 mutations/microdeletions (7-54 years), and 20 healthy controls (4-32 years) received neurocognitive assessments. Deletion boundaries for the subjects in the WAGR group were determined by high-resolution oligonucleotide array comparative genomic hybridization. Within the WAGR group, BDNF+/- subjects (n = 15), compared with BDNF intact (+/+) subjects (n = 13), had lower adaptive behaviour (p = .02), reduced cognitive functioning (p = .04), higher levels of reported historical (p = .02) and current (p = .02) social impairment, and higher percentage meeting cut-off score for autism (p = .047) on Autism Diagnostic Interview-Revised. These differences remained nominally significant after adjusting for visual acuity. Using diagnostic measures and clinical judgement, 3 subjects (2 BDNF+/- and 1 BDNF+/+) in the WAGR group (10.7%) were classified with autism spectrum disorder. A comparison group of visually impaired subjects with isolated aniridia had cognitive functioning comparable to that of healthy controls. In summary, among subjects with WAGR syndrome, BDNF+/- subjects had a mean Vineland Adaptive Behaviour Compose score that was 14-points lower and a mean intelligence quotient (IQ) that was 20-points lower than BDNF+/+ subjects. Our findings support the hypothesis that BDNF plays an important role in human neurocognitive development.