Novel and recurrent COL11A1 and COL2A1 mutations in the Marshall-Stickler syndrome spectrum

Hereditary Vitreoretinopathies: Molecular Diagnosis, Clinical Presentation and Management

Hereditary vitreoretinopathies (HVRs), also known as hereditary vitreoretinal degenerations comprise a heterogeneous group of inherited disorders of the retina and vitreous, collectively and variably characterised by vitreal abnormalities, such as fibrillary condensations, liquefaction or membranes, as well as peripheral retinal abnormalities, vascular changes in some, an increased risk of retinal detachment and early-onset cataract formation. The pathology often involves the vitreoretinal interface in some, while the major underlying abnormality is vascular in others. Recent advances in molecular diagnosis and identification of the responsible genes and have improved our understanding of the pathogenesis, risks and management of the HVRs. Clinically, HVRs can be classified according to the presence or absence of skeletal or other systemic abnormalities, retinal dysfunction or retinal vascular abnormalities [2]. There are some discrepancies in the literature regarding which diseases are included under the overarching term 'hereditary vitreoretinopathies'. Conditions such as Stickler syndrome, Wagner syndrome and familial exudative vitreoretinopathy are generally included, while others such as autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV) and autosomal dominant vitreoretinochoroidapathy (ADVIRC) may not. In this review, we will discuss some historical aspects, the molecular pathogenesis, clinical features and management of diseases and syndromes commonly considered as HVRs.

Ophthalmic Manifestations in a Diverse Pediatric Population with Type I and Type II Stickler Syndrome

OBJECTIVE

To characterize and compare our cohorts of pediatric patients with types I and II Stickler syndrome, with a focus on ophthalmic features.

DESIGN

Retrospective cohort study.

SUBJECTS

Twenty-six patients (22 families) with clinical and genetic diagnoses of type I or II Stickler syndrome.

METHODS

Review of clinical notes and molecular diagnoses.

MAIN OUTCOME MEASURES

Ophthalmic and systemic features and responses to laser treatment.

RESULTS

Our cohorts had an equal number of patients with COL2A1-related/type I and COL11A1-related/type II Stickler syndrome (n = 13; 50%) and included 12 previously unpublished variants. Patients in type I and II cohorts had similar average ages at presentation and length of follow-up. There were more self-identifying Hispanic patients among the type II cohort than type I (69% vs. 39%, P = 0.145). Individuals with type II on average had significantly higher myopia compared with those with type I (P = 0.008). Retinal detachment (RD) in at least 1 eye was diagnosed in 39% of the type I cohort (7 eyes, 5 patients) and 46% of the type II (7 eyes, 6 patients). Laser prophylaxis was used in 69% of patients with type I and 85% with type II. Unilateral RD after laser prophylaxis occurred in 1 patient with type I and 2 with type II. All identified COL2A1 variants in the type I cohort are expected to cause disease through haploinsufficiency, and 92% of COL11A1 variants in the type II cohort are presumed to be in-frame and exert a dominant-negative effect, consistent with historical reporting.

CONCLUSIONS

The proportion of types I and II Stickler syndrome are equal in our pediatric population, and patients self-identifying as Hispanic comprised the majority of type II, supporting the need for additional study of possible underdetection of type II in diverse populations. Our type II cohort showed higher myopia and incidence of Pierre Robin sequence, and similar rates of RD and systemic manifestations compared with the type I cohort. Our data sets provide important data regarding the safety and short-term effectiveness of laser prophylaxis, but larger and longer-term studies are needed, especially for those with type II Stickler syndrome.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Microphthalmia and congenital cataract in two patients with Stickler syndrome type II: a case report

BACKGROUND

Stickler syndrome (STL) is a collagenopathy caused by pathogenic variants in collagen-coding genes, mainly COL2A1 or COL11A1 associated with Stickler syndrome type 1 (STL1) or type 2 (STL2), respectively. Affected individuals manifest ocular, auditory, articular, and craniofacial findings in varying degrees. Previous literature and case reports describe high variability in clinical findings for patients with STL. With this case report, we broaden the clinical spectrum of the phenotype.

MATERIALS AND METHODS

Case report on two members of a family (mother and son) including clinical examination and genetic testing using targeted trio whole exome sequencing (trio-WES).

RESULTS

A boy and his mother presented with microphthalmia, congenital cataract, ptosis, and moderate-to-severe sensorineural hearing loss. Trio-WES found a novel heterozygote missense variant, c.4526A>G; p(Gln1509Arg) in COL11A1 in both affected individuals.

CONCLUSIONS

We report a previously undescribed phenotype associated with a COL11A1-variant in a mother and son, expanding the spectrum for phenotype-genotype correlation in STL2, presenting with microphthalmia, congenital cataract, and ptosis not normally associated with Stickler syndrome.

Tendon-associated gene expression precedes osteogenesis in mid-palatal suture establishment

Orthodontic maxillary expansion relies on intrinsic mid-palatal suture mechanobiology to induce guided osteogenesis, yet establishment of the mid-palatal suture within the continuous secondary palate and causes of maxillary insufficiency remain poorly understood. In contrast, advances in cranial suture research hold promise to improve surgical repair of prematurely fused cranial sutures in craniosynostosis to potentially restore the obliterated signaling environment and ensure continual success of the intervention. We hypothesized that mid-palatal suture establishment is governed by shared principles with calvarial sutures and involves functional linkage between expanding primary ossification centres with the midline mesenchyme. We characterized establishment of the mid-palatal suture from late embryonic to early postnatal timepoints. Suture establishment was visualized using histological techniques and multimodal transcriptomics. We identified that mid-palatal suture formation depends on a spatiotemporally controlled signalling milieu in which tendon-associated genes play a significant role. We mapped relationships between extracellular matrix-encoding gene expression, tenocyte markers, and novel suture patency candidate genes. We identified similar expression patterns in FaceBase-deposited scRNA-seq datasets from cranial sutures. These findings demonstrate shared biological principles for suture establishment, providing further avenues for future development and understanding of maxillofacial interventions.

A Novel COL2A1 Gene Pathogenic Variant in a Turkish Family With Ocular Stickler Syndrome

A 6-month-old female infant with megalophthalmos was referred with the suspicion of congenital glaucoma. Refractive measurements obtained with handheld autorefractometry were -7.00 -2.00 × 90° in the right eye and -6.00 -2.00 × 100° in the left eye and ultrasonic axial lengths were 22.50 mm in both eyes. Intraocular pressures and vertical and horizontal corneal diameters of the proband were 11 mm Hg, 11 mm, and 11.50 mm in both eyes, respectively. She was diagnosed as having early-onset high myopia. Her father also had degenerative high myopia (-12.00 diopters) in the right eye, bilateral congenital lens opacities, and retinal detachment in the left eye. Her mother was emmetropic with normal eye examination results. Clinical exome sequencing analysis revealed a novel ENST00000380518.3 c.3528_3530 delins GACCATTAGCA (Chr12:48369813: GCA > TGCTAATGGTC) variant in the collagen type II alpha 1 chain (COL2A1) on chromosome 12q13 (OMIM 108300), consistent with the Stickler syndrome type 1. Subsequent segregation analysis revealed paternal inheritance. Although many pathogenic null variants have been described within the COL2A1 gene, there is currently no documented literature pertaining to this specific variant, making this the inaugural report of its manifestation in scientific discourse. [J Pediatr Ophthalmol Strabismus. 2024;61(3):e23-e27.].

Genetically inspired organoids prevent joint degeneration and alleviate chondrocyte senescence via Col11a1-HIF1α-mediated glycolysis-OXPHOS metabolism shift

INTRODUCTION

Developmental dysplasia of hip (DDH) is a hip joint disorder leading to subsequent osteoarthritis. Previous studies suggested collagen XI alpha 1 (COL11A1) as a potential gene in hip dysplasia and chondrocyte degeneration. However, no genetic association has reported COL11A1-related cellular therapy as treatment of DDH and joint degeneration.

METHODS AND RESULTS

We report identified genetic association between COL11A1 locus and DDH with genome-wide association study (GWAS). Further exome sequencing for familial DDH patients was conducted in different populations to identify potential pathogenic Col11A1 variants for familiar DDH. Further studies demonstrated involvement of COL11A1 expression was down-regulated in femoral head cartilage of DDH patients and Col11a1-KO mice with induced DDH. Col11a1-KO mice demonstrated aggravated joint degeneration and severe OA phenotype. To explore the underlying mechanism of Col11a1 in cartilage and DDH development, we generated scRNA-seq profiles for DDH and Col11a1-KO cartilage, demonstrating disrupted chondrocyte homeostasis and cellular senescence caused by Col11a1-HIF1α-mediated glycolysis-OXPHOS shift in chondrocytes. Genetically and biologically inspired, we further fabricated an intra-articular injection therapy to preventing cartilage degeneration by generating a Col11a1-over-expressed (OE) SMSC mini-organoids. Col11a1-OE organoids demonstrated superior chondrogenesis and ameliorated cartilage degeneration in DDH mice via regulating cellular senescence by up-regulated Col11a1/HIF1α-mediated glycolysis in chondrocytes.

CONCLUSION

We reported association between COL11A1 loci and DDH with GWAS and exome sequencing. Further studies demonstrated involvement of COL11A1 in DDH patients and Col11a1-KO mice. ScRNA-seq for DDH and Col11a1-KO cartilage demonstrated disrupted chondrocyte homeostasis and cellular senescence caused by Col11a1-HIF1α-mediated glycolysis-OXPHOS shift in chondrocytes. Genetically and biologically inspired, an intra-articular injection therapy was fabricated to prevent cartilage degeneration with Col11a1-OE SMSC organoids. Col11a1-OE organoids ameliorated cartilage degeneration in DDH mice via regulating cellular senescence by up-regulated Col11a1/HIF1α-mediated glycolysis in chondrocytes.

The cochlear matrisome: Importance in hearing and deafness

The extracellular matrix (ECM) consists in a complex meshwork of collagens, glycoproteins, and proteoglycans, which serves a scaffolding function and provides viscoelastic properties to the tissues. ECM acts as a biomechanical support, and actively participates in cell signaling to induce tissular changes in response to environmental forces and soluble cues. Given the remarkable complexity of the inner ear architecture, its exquisite structure-function relationship, and the importance of vibration-induced stimulation of its sensory cells, ECM is instrumental to hearing. Many factors of the matrisome are involved in cochlea development, function and maintenance, as evidenced by the variety of ECM proteins associated with hereditary deafness. This review describes the structural and functional ECM components in the auditory organ and how they are modulated over time and following injury.

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.

Stickler and Wagner Syndrome in African Americans

BACKGROUND

Stickler (STL) and Wagner (WGN) syndromes are rare inherited vitreoretinopathies associated with retinal detachments (RD). There is a paucity of case reports describing these diseases in African American patients.

METHODS

An IRB-approved, retrospective chart review of African American patients with genetically proven ocular-only STL or WGN was performed, and 6 patients were identified.

RESULTS

Three patients had a COL2A1 mutation, two had a COL11A1 mutation, and one had a VCAN mutation. None had Pierre Robin facies. All were myopes with lattice degeneration and five had RD. Three underwent RD repair with vitrectomy (PPV), scleral buckle (SB), endolaser (EL), and silicone oil (SO). Two received laser retinopexy for localized RD and one received a prophylactic SB with 360° peripheral laser retinopexy.

CONCLUSION

STL and WGN should be considered in myopic African American patients with lattice degeneration, giant retinal tears, abnormal vitreous, or spontaneous RD. Prophylactic laser treatment and aggressive surgical treatment of RD should be considered. [Ophthalmic Surg Lasers Imaging Retina 2023;54:97-101.].

Spontaneous lens resorption in a patient with Marshall-Stickler Syndrome and glaucoma

Purpose

The purpose of this case report is to describe the increased fragility of anterior capsule in patients with the rare genetic disease Marshall-Stickler syndrome.

Observations

We describe a 3-year old patient with Marshall-Stickler Syndrome and congenital glaucoma treated with glaucoma drainage implant placement who subsequently developed spontaneous lens resorption in one eye, which was noted incidentally during one follow-up appointment.

Conclusions and Importance

It is hypothesized that the lens material left the eye through the glaucoma drainage implant over time. This process was not associated with elevation of intraocular pressures or inflammation and did not require subsequent surgery to remove any residual lens fragments, which has not been reported before to the best of the authors’ knowledge.

High Myopia and Strabismus Induced by a Deep Intronic Mutation in COL2A1

Purpose: To characterize a genetic mutation causing Stickler syndrome in a previously undiagnosed family.Methods: Five generations of a single family suspected of having Stickler syndrome were evaluated clinically and genetically.Results: The demographic and clinical data yielded specific clinical phenotypes of Stickler syndrome in 13 family members; 7 had more than one clinical feature. Four family members underwent genetic analysis: the proband (index patient) and his mother, maternal grandfather, and healthy father. No relevant mutation was detected in the proband on whole exome analysis, but subsequent extension of the analysis to intronic areas yielded a deep intronic mutation, NM_001844.5:c.1527 + 135 G > A. Sanger sequencing was used to validate the results in the family members.Conclusions: Stickler syndrome has several subtypes with variable clinical features. Therefore, predicting the genetic locus of the disease based on clinical characteristics is challenging. We present a rarely described intronic mutation in COL2A1. Genetic testing may aid in the early diagnosis of Stickler syndrome, which is important for genetic counselling, proper clinical management, and improved prognosis.

Genetics and signaling mechanisms of orofacial clefts

Craniofacial development involves several complex tissue movements including several fusion processes to form the frontonasal and maxillary structures, including the upper lip and palate. Each of these movements are controlled by many different factors that are tightly regulated by several integral morphogenetic signaling pathways. Subject to both genetic and environmental influences, interruption at nearly any stage can disrupt lip, nasal, or palate fusion and result in a cleft. Here, we discuss many of the genetic risk factors that may contribute to the presentation of orofacial clefts in patients, and several of the key signaling pathways and underlying cellular mechanisms that control lip and palate formation, as identified primarily through investigating equivalent processes in animal models, are examined.

Variable clinical expression of Stickler Syndrome: A case report of a novel COL11A1 mutation

Background

Stickler Syndrome is a rare connective tissue disorder, characterized by clinical, and genetic heterogeneity. The clinical expression is highly variable, including moderate to severe myopia in childhood, hearing loss, facial dysmorphic features, cleft palate, and early osteoarthritis. COL2A1, COL11A1, and COL11A2 mutations account of the majority of autosomal dominant Stickler Syndrome and, in particular, a heterozygous mutation in COL11A1 gene is identified in about 10 to 20% of Stickler Syndrome patients.

Methods

Herein, we report a case of an 8‐year‐ old child with Stickler Syndrome, presenting with early‐onset of myopia with vitreal abnormalities, facial dysmorphic characteristics, and mild hearing loss later in childhood. To identify the underlying genetic cause, Whole Exome Sequencing was carried out for COL11A1 gene.

Results

A novel de novo heterozygous splice site variant (NM_001854: c.1845 + 5G> C) of the COL11A1 gene, which had not been previously reported, was identified by Whole Exome Sequencing.

Conclusion

We reported a novel COL11A1 mutation in a child with Stickler Syndrome presenting a phenotype of early‐onset of ocular anomalies and mild hearing loss later in childhood. Our findings confirm the variability of the expression of the disease, even in the contest of the same gene‐related disorder, thus, contributing to improve the knowledge on clinical and molecular basis of this rare disease.

Audiologic Manifestations of Marshall Syndrome

OBJECTIVE

Marshall syndrome is a genetic disorder caused by mutations in the COL11A1 gene. This syndrome is characterized by skeletal, ophthalmologic, craniofacial, and auditory abnormalities. Hearing loss is among the main manifestations reported in this disorder being observed in approximately 80% of affected individuals.The present study aims to describe the audiologic characteristics of three members of a family with Marshall syndrome and also serves as a review of the literature.

STUDY DESIGN

Family study.

SETTING

Tertiary care otology and skull base center.

PATIENTS

We report the audiologic findings in a family with Marshall syndrome consisting of a mother and her son and daughter.

INTERVENTION(S)

The audiologic evaluation included tympanometry, acoustic reflexes testing, auditory brainstem response, transient otoacoustic emissions, pure-tone audiometry, speech audiometry in quiet, and conditioned play audiometry. These methods were applied according to the age of the patients. In addition, we provide a review of the English-language literature in an attempt to clarify the auditory phenotype of this syndrome.

RESULTS

All 3 affected individuals had heterozygous c.3816+1G>A mutation in the splicing donor site of intron 50 of the COL11A1 gene. All three patients in our study had bilateral sensorineural hearing loss. Hearing impairment ranged from mild to moderate in the daughter, moderate in the son, and from mild to moderate in their mother.

CONCLUSION

The majority of individuals with Marshall syndrome present early-onset bilateral sensorineural hearing loss. Hearing impairment is usually detected in early childhood, progresses gradually, and becomes stable in late adulthood, with a severity ranging from mild to severe.