Is exon 8 the most critical or the only dispensable exon of the VCAN gene? Insights into VCAN variants and clinical spectrum of Wagner syndrome.

Wagner syndrome and erosive vitreoretinopathy together constitute the phenotypic continuum of an autosomal dominant vitreoretinopathy, with clinical findings typically isolated to the eye. The disease is caused by pathogenic variants in the VCAN gene and all such variants reported to date are those that plausibly result in haploinsufficiency of exon 8 containing vcan transcripts. Here, we report the molecular findings and long-term follow-up of a 16-year-old female with a history of retinal detachments and pigmentary retinal changes. Next-generation sequencing and microarray analysis of 141 genes established a diagnosis of Wagner syndrome in this individual, by detection of an 11.7 kilobase (kb) deletion encompassing exon 8 of VCAN. In light of the emerging functions and roles of versican protein in human disease, we discuss how variants within exon 8 of the VCAN gene can be compared to those in exon 2 of the COL2A1 gene that cause atypical Stickler syndrome and propose that variants in other regions of the gene can be expected to present with a more systemic disease. The distinctive facial features and atypical gastrointestinal symptoms observed in this long-term follow-up study support the possibility that individuals with VCAN-related vitreoretinopathy may have extra-ocular clinical features.

WAGNER syndrome: anatomic, functional and genetic characterization of a Portuguese family.

PURPOSE: To report the clinical (anatomic and functional) and genetic findings of Wagner Syndrome (WS) in a Portuguese family. METHODS: Nine members of the family agreed to be examined. All had complete clinical eye examinations. The proband and selected patients underwent color fundus photography, spectral domain optical coherence tomography (SD-OCT), automatic static white-on-white computerized perimetry, and electrophysiology assessment (flash ERG, multifocal(mf) ERG and dark adaptometry). A pedigree was constructed based on interviews with known affected subjects. Genomic DNA samples derived from venous blood were collected from all affected family members examined. RESULTS: Twenty-eight family members are affected. This family has the typical features of Wagner Syndrome, namely an empty vitreous cavity with veils, mild myopia and cataract. Four examined patients underwent vitreoretinal surgery due to abnormal peripheral vitreoretinal adhesions with peripheral retinal traction (n = 3). Retinal detachment was observed in 5 of the examined subjects. Four of them occurred between the ages of 5 and 15 years. Chorioretinal atrophy is also a frequent finding which results in moderate to severe visual field and advanced rod-cone dystrophy from younger ages, also confirmed by absence of scotopic function on dark adaptation. The macular dysfunction on mfERG was profound and of early onset. A heterozygous mutation in intron 7 of the VCAN gene (c.4004-1G > A) was found. CONCLUSIONS: We described a rare autosomal dominant vitreoretinopathy with near complete penetrance in a Portuguese family. Abnormal peripheral vitreoretinal adhesions, retinal detachment and chorioretinal atrophy are present in most of the examined individuals at young ages. Early onset of advanced visual field and electrophysiologic abnormalities were observed in this family. We also added relevant information to the literature by reporting our experience in surgical management of Wagner Syndrome patients with, and at risk of, retinal detachment.

Multimodal Evaluation and Management of Wagner Syndrome-Three Patients from an Affected Family.

Wagner syndrome is a rare autosomal dominant vitreoretinopathy caused by mutations in chondroitin sulphate proteoglycan 2 (CSPG2)/Versican (VCAN). Here, we present a retrospective case series of a family pedigree with genetically confirmed Wagner syndrome (heterozygous VCAN exon 8 deletion), as follows: a 34-year-old mother (P1), 12-year-old daughter (P2), and a 2-year-old son (P3). The phenotype included early-onset cataract (P1), optically empty vitreous with avascular membranes (P1, 2), nasal dragging of optic nerve heads associated with foveal hypoplasia (P1, 2), tractional retinoschisis on optical coherence tomography (P2), and peripheral circumferential vitreo-retinal interface abnormality resembling white-without-pressure (P3) progressing to pigmented chorio-retinal atrophy (P1, 2). P2 developed a macula-off retinal detachment, which was treated initially with encircling band + vitrectomy + gas, followed by vitrectomy + heavy silicone oil tamponade for re-detachment from new inferior breaks. Strong vitreo-retinal adhesion was noted intraoperatively, which prevented the separation of posterior hyaloid beyond the equator. Electroretinograms from P1&2 demonstrated attenuated b-waves, a-waves, and flicker responses in light- and dark-adapted conditions, suggestive of generalised retinal dysfunction. Our patients demonstrated the clinical spectrum of Wagner syndrome, highlighting nasal dragging with foveal disruption as a distinguishing feature from other inherited vitreoretinopathies. Surgical outcomes demonstrate significant challenges in managing vitreo-retinal traction and need for further research into strategies to prevent sight loss.

Wagner syndrome: Novel VCAN variant and prophylactic management with encircling band and retinopexy.

Purpose: Wagner syndrome is an autosomal genetic vitreoretinopathy characterized by chorioretinal atrophy, avascular vitreous veils, reduced visual acuity and early retinal detachment in advanced cases. Management of Wagner syndrome usually results in observation then management of occurring complications. Observations: We report the case of a 9-year-old girl presenting with supposed Wagner syndrome that we managed with prophylactic encircling band and retinopexy in both eyes. The genetic testing revealed a new variant in the intron 7 non canonical splice acceptor site, c.4004-12_4004-6delins17, that was also present in her father. Conclusions and Importance: The VCAN variant found in this proband and her father has not been described yet but shows high predictions of pathogenicity. The previous reported variants in VCAN intron 7 and the associated phenotype for both cases allowed us to attribute this variant to Wagner syndrome. In Wagner syndrome, management is usually curative. After prophylactic surgery in our case, the zones of retinal delamination were well supported by the scleral buckle, releasing the vitreoretinal tractions, and the additional laser focalized on the temporal zones of dehiscence secured the retina. An encircling band may be a good way to prevent RD in patients with Wagner syndrome at risk.

Controversy and Consideration of Refractive Surgery in Patients with Heritable Disorders of Connective Tissue.

Heritable Disorders of Connective Tissue (HDCTs) are syndromes that disrupt connective tissue integrity. They include Osteogenesis Imperfecta (OI), Ehlers Danlos Syndrome (EDS), Marfan Syndrome (MFS), Loeys-Dietz Syndrome (LDS), Epidermolysis Bullosa (EB), Stickler Syndrome (STL), Wagner Syndrome, and Pseudoxanthoma Elasticum (PXE). Because many patients with HDCTs have ocular symptoms, commonly myopia, they will often present to the clinic seeking refractive surgery. Currently, corrective measures are limited, as the FDA contraindicates laser-assisted in-situ keratomileusis (LASIK) in EDS and discourages the procedure in OI and MFS due to a theoretically increased risk of post-LASIK ectasia, poor wound healing, poor refractive predictability, underlying keratoconus, and globe rupture. While these disorders present with a wide range of ocular manifestations that are associated with an increased risk of post-LASIK complications (e.g., thinned corneas, ocular fragility, keratoconus, glaucoma, ectopia lentis, retinal detachment, angioid streaks, and ocular surface disease), their occurrence and severity are highly variable among patients. Therefore, an HDCT diagnosis should not warrant an immediate disqualification for refractive surgery. Patients with minimal ocular manifestations can consider LASIK. In contrast, those with preoperative signs of corneal thinning and ocular fragility may find the combination of collagen cross-linking (CXL) with either photorefractive keratotomy (PRK), small incision lenticule extraction (SMILE) or a phakic intraocular lens (pIOL) implant to be more suitable options. However, evidence of refractive surgery performed on patients with HDCTs is limited, and surgeons must fully inform patients of the unknown risks and complications before proceeding. This paper serves as a guideline for future studies to evaluate refractive surgery outcomes in patients with HDCTs.

Homozygous Recessive Versican Missense Variation Is Associated With Early Teeth Loss in a Pakistani Family.

Only a few genes involved in teeth development and morphology are known to be responsible for tooth abnormalities in Mendelian-inherited diseases. We studied an inbred family of Pakistani origin in which two first-cousin born brothers are affected by early tooth loss with peculiar teeth abnormalities characterized by the absence of cementum formation. Whole exome sequencing revealed a H2665L homozygous sequence variant in the VCAN gene. Dominant splicing mutations in VCAN are known to cause Wagner syndrome or vitreoretinopathy. We explored teeth morphology in these two patients, while versican expression was assessed by western blot analysis. Early signs of vitreoretinopathy were found in the elder brother while the parents were completely negative. Our findings suggest that the homozygous recessive H2665L missense sequence variant impairs the normal morphology of the teeth roots via loss of cementum synthesis, and is also associated with early onset, recessive, Wagner syndrome, thus expanding both the phenotype mutation scenario and the inheritance mode of VCAN mutations.

Reduced penetrance in a large Caucasian pedigree with Stickler syndrome.

BACKGROUND: In a four-generation Caucasian family variably diagnosed with autosomal dominant (AD) Stickler or Wagner disease, commercial gene screening failed to identify a mutation in COL2A1 or VCAN. We utilized linkage mapping and exome sequencing to identify the causal variant. MATERIALS AND METHODS: Genomic DNA samples collected from 40 family members were analyzed. A whole-genome linkage scan was performed using Illumina HumanLinkage-24 BeadChip followed by two-point and multipoint linkage analyses using FASTLINK and MERLIN. Exome sequencing was performed on two affected individuals, followed by co-segregation analysis. RESULTS: Parametric multipoint linkage analysis using an AD inheritance model demonstrated HLOD scores > 2.00 at chromosomes 1p36.13-1p36.11 and 12q12-12q14.1. SIMWALK multipoint analysis replicated the peak in chromosome 12q (peak LOD = 1.975). FASTLINK two-point analysis highlighted several clustered chromosome 12q SNPs with HLOD > 1.0. Exome sequencing revealed a novel nonsense mutation (c.115C>T, p.Gln39*) in exon 2 of COL2A1 that is expected to result in nonsense-mediated decay of the RNA transcript. This mutation co-segregated with all clinically affected individuals and seven individuals who were clinically unaffected. CONCLUSIONS: The utility of combining traditional linkage mapping and exome sequencing is highlighted to identify gene mutations in large families displaying a Mendelian inheritance of disease. Historically, nonsense mutations in exon 2 of COL2A1 have been reported to cause a fully penetrant ocular-only Stickler phenotype with few or no systemic manifestations. We report a novel nonsense mutation in exon 2 of COL2A1 that displays incomplete penetrance and/or variable age of onset with extraocular manifestations.