Retinal findings and a novel TINF2 mutation in Revesz syndrome: Clinical and molecular correlations with pediatric retinal vasculopathies

The genetics and disease mechanisms of rhegmatogenous retinal detachment

Rhegmatogenous retinal detachment (RRD) is a sight threatening condition that warrants immediate surgical intervention. To date, 29 genes have been associated with monogenic disorders involving RRD. In addition, RRD can occur as a multifactorial disease through a combined effect of multiple genetic variants and non-genetic risk factors. In this review, we provide a comprehensive overview of the spectrum of hereditary disorders involving RRD. We discuss genotype-phenotype correlations of these monogenic disorders, and describe genetic variants associated with RRD through multifactorial inheritance. Furthermore, we evaluate our current understanding of the molecular disease mechanisms of RRD-associated genetic variants on collagen proteins, proteoglycan versican, and the TGF-β pathway. Finally, we review the role of genetics in patient management and prevention of RRD. We provide recommendations for genetic testing and prophylaxis of at-risk patients, and hypothesize on novel therapeutic approaches beyond surgical intervention.

Genetics of human telomere biology disorders

Telomeres are specialized nucleoprotein structures at the ends of linear chromosomes that prevent the activation of DNA damage response and repair pathways. Numerous factors localize at telomeres to regulate their length, structure and function, to avert replicative senescence or genome instability and cell death. In humans, Mendelian defects in several of these factors can result in abnormally short or dysfunctional telomeres, causing a group of rare heterogeneous premature-ageing diseases, termed telomeropathies, short-telomere syndromes or telomere biology disorders (TBDs). Here, we review the TBD-causing genes identified so far and describe their main functions associated with telomere biology. We present molecular aspects of TBDs, including genetic anticipation, phenocopy, incomplete penetrance and somatic genetic rescue, which underlie the complexity of these diseases. We also discuss the implications of phenotypic and genetic features of TBDs on fundamental aspects related to human telomere biology, ageing and cancer, as well as on diagnostic, therapeutic and clinical approaches.

Explore the molecular mechanism of angle-closure glaucoma in elderly patients induced telomere shortening of retinal ganglion cells through oxidative stress

Senile glaucoma is a common ophthalmological disease in the elderly. It is a disease of visual papillary perfusion caused by elevated intraocular pressure, complicated by visual dysfunction. Glaucoma can cause serious damage to the normal vision of the elderly. Therefore, exploring the related molecular mechanisms of glaucoma is of great significance to the diagnosis and treatment of glaucoma. This is an exploratory study. Establish a mouse model and conduct experimental groupings. After one week of adaptive feeding, the mice were intraperitoneally injected with an anesthetic mixture: ketamine + xylazine. Then the mice were sacrificed by neck dissection, and the eyeball tissues were immediately dissected. HE staining was used to analyze the histopathological characteristics of the retina of each group of mice. MitoSOX fluorescent probe was used to analyze the content of ROS in retinal tissue. The ELISA analysis was used to detect the activation of β-galactosidase for the aging characteristics of retinal ganglion cells in retinal tissues. Immunohistochemistry experiments were used to analyze the expression of telomerase TERT in retinal tissues. Western blot analysis was used to determine the expression of proteins POT1, TERF1, TERF2, and TINF2 in retinal tissues. The HE staining experiment showed that the damage of retinal tissue decreased from group Glaucoma to group Old, group Old to group Young. The experimental results of MitoSOX fluorescent probe show that ROS content is positively correlated with the degree of tissue damage. ELISA analysis results showed that the expression trend of β-galactosidase was the same as the ROS content. The protein expression levels related to telomere protection (TRET, POT1, TREF1, TREF2 and TINF2) all increased from group Glaucoma to group Old, group Old to group Young. The increase in ROS content, the decrease in telomere protection-related protein expression (telomere shortening) induced by ROS, and the increase of the expression of β-galactosidase, are all potential molecular mechanisms for the occurrence of angle-closure glaucoma in elderly patients.

The Masquerading Retinopathy of Revesz Syndrome

Revesz syndrome is a rare telomeropathy characterized by bone marrow failure and exudative retinopathy. We report the case of a 2-year-old male child, initially treated with bilateral laser photocoagulation for retinopathy of prematurity. He developed exudative changes in the right eye, presumed to be Coats disease. Later, the left eye developed a total vitreous hemorrhage. Proliferative retinopathy was noted intraoperatively. Systemic features of bone marrow failure, growth retardation, and nail pigmentation were present. Genetic testing confirmed the diagnosis of Revesz syndrome. We describe our approach to diagnosis and surgical management of the case. [Ophthalmic Surg Lasers Imaging Retina 2022;53(6): 346-348.].

Retinal Features of Family Members With Familial Exudative Vitreoretinopathy Caused By Mutations in KIF11 Gene

Purpose

To determine the clinical characteristics of patients and family members with familial exudative vitreoretinopathy (FEVR) caused by mutations in the KIF11 gene.

Methods

Twenty-one patients from 10 FEVR families with mutations in the KIF11 gene were studied. The retinal and systemic features were examined. The genetic analyses performed included Sanger sequencing of the KIF11 gene, whole exome sequencing, as well as array comparative genomic hybridization (CGH) analysis and multiple ligation probe assay (MLPA).

Results

Sequence analysis revealed seven different KIF11 mutations. Array CGH with MLPA revealed two different exon deletions. All probands had advanced FEVR with retinal detachments (RDs) and microcephaly with or without developmental disabilities. Patients with bilateral RDs were more frequently associated with developmental disabilities (P = 0.023). Multimodal imaging of the family members revealed that six of nine patients without RDs (66%) had varying degrees of chorioretinopathy. The retinal folds in FEVR patients were associated with severe retinal avascularization. However, funduscopic changes in the peripheral retina were unremarkable in family members without RDs. A score representing the peripheral vascular anomalies determined from the fluorescein angiograms was lower than that of control eyes of patients with mutations of the Wnt signaling genes (P = 0.0029).

Conclusions

The probands with KIF11 mutations were associated with severe ocular and systemic pathologies, whereas affected family members showed highly variable clinical manifestations. Peripheral vascular anomalies can often be unremarkable in eyes without RDs.

Translational Relevance

These findings highlight more diverse mechanisms that underlie the pathological changes in patients with FEVR.

Revesz syndrome with bilateral retinal detachments successfully treated by pars plana vitrectomy

Background

Revesz syndrome is a rare type of the dyskeratosis congenita spectrum disorder that is characterized by nail dystrophy, oral leukoplakia, and abnormal skin pigmentation. The retinal features are similar to those of exudative retinopathy with avascular areas of the peripheral retina. There are only a few publications describing patients with Revesz syndrome who underwent ocular treatments for the retinal complications. We report a Case of Revesz syndrome with bilateral retinal detachments that were successfully reattached by pars plana vitrectomy.

Observations

A 3-year-old Japanese girl with Revesz Syndrome had progressive vitreal hemorrhages and tractional retinal detachments in both eyes. She underwent pars plana vitrectomy with lensectomy on both eyes. A retinal attachment with vision improvement was achieved by a single surgery for the right eye and after repeated surgeries for the left eye. Postoperative electroretinographic (ERG) examinations of the right eye showed a negative type ERG with the b-wave/a-wave ratio <1.0. There were extensive areas of avascular retina detected by fluorescein angiography and a thinning of the inner and outer retina detected by optical coherence tomography.

Conclusion and importance

Pars plana vitrectomy can effectively treat the extensive retinal detachment in an eye with Revesz syndrome. However, postoperative retinal ischemia can be detected by careful imaging.

Revesz syndrome revisited

Background

Revesz syndrome (RS) is an extremely rare variant of dyskeratosis congenita (DKC) with only anecdotal reports in the literature.

Methods

To further characterize the typical features and natural course of the disease, we screened the English literature and summarized the clinical and epidemiological features of previously published RS cases. In addition, we herein describe the first recorded patient in central Europe.

Results

The literature review included 18 children. Clinical features are summarized, indicating a low prevalence of the classical DKC triad. All patients experienced early bone marrow failure, in most cases within the second year of life (median age 1.5 years; 95% CI 1.4–1.6). Retinopathy occurred typically between 6 and 18 months of age (median age 1.1 years; 95% CI 0.7–1.5). The incidence of seizures was low and was present in an estimated 20% of patients. The onset of seizures was exclusively during early childhood. The Kaplan–Meier estimate of survival was dismal (median survival 6.5 years; 95% CI 3.6–9.4), and none of the patients survived beyond the age of 12 years. Stem cell transplantation (SCT) was performed in eight children, and after a median of 22 months from SCT four of these patients were alive at the last follow up visit.

Conclusion

RS is a severe variant of DKC with early bone marrow failure and retinopathy in all patients. Survival is dismal, but stem cell transplantation may be performed successfully and might improve prognosis in the future.

Ophthalmic findings and a novel CTC1 gene mutation in coats plus syndrome: a case report

BACKGROUND

Coats plus syndrome is a rare multisystem disorder, and is also a telomere-related disorder caused by CTC1 gene mutation. We reported ophthalmic findings in a Chinese child with genetically confirmed Coats plus syndrome.

MATERIALS AND METHODS

The comprehensive ophthalmic findings were presented, as well as treatment history and systemic manifestations. In addition, genetic testing was performed to confirm the diagnosis.

RESULTS

Examination under anesthesia showed notable retinal vasculopathy, including vascular tortuosity and dilation, abnormal vascular anastomosis, retinal telangiectasias and mild exudation, extensive peripheral avascularity, as well as the presence of retinal neovascularization. The patient developed vitreous hemorrhage and tractional retinal detachment, and then underwent vitrectomy. Meanwhile, the patient was noted to have growth retardation and leukoencephalopathy. Gene testing identified a compound heterozygous mutation in CTC1 gene: a novel splicing site mutation (c.33 + 1 G > T) and a deletion mutation (c.2954_2956del, p.C985del), which were inherited from his mother and father, respectively.

CONCLUSIONS

The present report expanded the genotype and phenotype spectrum of CTC1 gene associated with Coats plus syndrome.

Retinal manifestations of the neurocutaneous disorders

PURPOSE OF REVIEW

The neurocutaneous disorders are a genetically and phenotypically diverse group of congenital syndromes characterized by cutaneous, ocular, and central nervous system manifestations. This review provides an overview of the clinical features and retinal findings in selected neurocutaneous disorders.

RECENT FINDINGS

Advances in genetics and diagnostic retinal and neuroimaging allow for the recognition of retinal features of common neurocutaneous syndromes and for improved characterization of rarer entities based on previously underdiagnosed or unrecognized retinal findings.

SUMMARY

Better characterization of the neurocutaneous disorders allows for earlier recognition and the potential for expeditious vision-saving and life-saving treatment.

Revesz syndrome masquerading as traumatic retinal detachment

A 13-month-old boy with mild hemophilia A presented for strabismus evaluation and was found to have retinal hemorrhages in the right eye, left exotropia, and left total retinal detachment. These findings were attributed to trauma and hemophilia A. Routine blood work for hemophilia A subsequently showed pancytopenia. A bone marrow aspirate showed marked hypocellularity consistent with severe aplastic anemia, and telomere testing revealed very short telomeres. The patient was found to have a TINF2 mutation consistent with a diagnosis of Revesz syndrome, a variant of dyskeratosis congenita. He underwent successful bone marrow transplantation, and on subsequent evaluation was found to have retinal hemorrhages, vessel sclerosis, and cotton wool spots in the right eye associated with peripheral retinal nonperfusion. He underwent retinal laser treatment to the areas of retinal nonperfusion which resulted in stable visual function.