Association of Somatic GNAQ Mutation With Capillary Malformations in a Case of Choroidal Hemangioma

Sporadic hypertrophic and nodular port-wine stain: a study of 27 cases with emphasis on histological features and novel mutation type

AIMS

To investigate the clinicopathological features and molecular characteristics of sporadic hypertrophic and nodular port-wine stains (PWS).

METHODS

We analysed the clinicopathological and molecular characteristics of 27 sporadic hypertrophic and nodular PWS retrieved from our pathology database from 2013 to 2023 and reviewed the relevant literature.

RESULTS

There were 13 men and 14 women who ranged in age from 10 to 66 years. The main sites were the head and neck (23/27, 85%), which showed irregular thickening and darkening of purplish-red patches on the skin surface and the development of nodularity. Histologically, immature venule-like channels with irregular dilation are arranged in clusters or honeycombs, which are widely distributed primarily in the papillary layer and deep dermis and partly extend into the subcutaneous fat layer and other deep tissues. Dilated vessels with irregular shapes often exhibit fibrous thickening and an increased number of large vessels without vascular endothelial cell proliferation. All vessels showed similar characteristics, with positive staining for CD34, ERG and GNAQ in the endothelial cells, and negative staining for elastic fibres. Nine patients had somatic GNAQ mutations (9/11, 82%), including exon four mutations (6 cases, p.R183Q), exon five mutations (2 cases, p.Q209R) and exon two mutations (one case, p.G48V). Two patients had somatic BCL6 corepressor-like 1 (BCORL1) gene mutations (2/11, 18%), including exon 3 mutations (p.T1111M) and exon 7 mutations (p.G1391R).

CONCLUSIONS

Sporadic hypertrophic and nodular PWS are mostly related to somatic GNAQ mutations. This is the first study to identify the Rare GNAQ G48V and somatic BCORL1 mutations.

Similarities and differences between brain and skin GNAQ p.R183Q driven capillary malformations

Capillary malformations (CM) are congenital vascular irregularities of capillary and venous blood vessels that appear in the skin, leptomeninges of the brain, and the choroid of the eye in the disorder known as Sturge Weber Syndrome (SWS). More common are non-syndromic CM found only in the skin, without brain or ocular involvement. A somatic activating mutation in GNAQ (p.R183Q) is found in ~ 90% of syndromic and non-syndromic CM specimens and is present in CD31pos endothelial cells isolated from brain and skin CM specimens. Endothelial expression of the GNAQ p.R183Q variant is sufficient to form CM-like vessels in mice. Given the distinct features and functions of blood vessels in the brain versus the skin, we examined the features of CM vessels in both tissues to gain insights into the pathogenesis of CM. Herein, we present morphologic characteristics of CM observed in specimens from brain and skin. The GNAQ p.R183Q variant allelic frequency in each specimen was determined by droplet digital PCR. Sections were stained for endothelial cells, tight junctions, mural cells, and macrophages to assess the endothelium as well as perivascular constituents. CM blood vessels in brain and skin were enlarged, exhibited fibrin leakage and reduced zona occludin-1 and claudin-5, and were surrounded by MRC1pos/LYVE1pos macrophages. In contrast, the CMs from brain and skin differ in endothelial sprouting activity and localization of mural cells. These characteristics might be helpful in the development of targeted and/or tissue specific therapies to prevent or reverse non-syndromic and syndromic CM.

THE RETINAL DEEP CAPILLARY PLEXUS AS A VENOUS OUTFLOW SYSTEM: INSIGHTS FROM STURGE-WEBER SYNDROME

PURPOSE

To report on the venous abnormalities of a patient with Sturge-Weber syndrome.

METHOD

Case report.

PATIENT

A 29-year-old woman with a history of Sturge-Weber syndrome since infancy was referred for evaluation of possible diffuse choroidal hemangioma. Multimodal imaging, including ultra-widefield fluorescein, indocyanine green, and optical coherence tomography angiography, was performed.

RESULTS

Dilated fundus examination was remarkable for increased cupping of the optic disk in the right eye, venous tortuosity, and marked dilation of the choroidal vessels. Ultra-widefield fluorescein angiography confirmed marked venous tortuosity and dilation, as well as anastomoses of the retinal veins ipsilateral to the port wine stain. Indocyanine green angiography revealed marked engorgement of the vortex veins and choroidal vasculature. Optical coherence tomography angiography revealed dilated vascular channels in the deep capillary plexus that were directly anastomosing to the superficial capillary plexus, but not the intermediate capillary plexus. Engorgement of the ampullae of the deep capillary plexus vortex system was also observed. The normal contralateral eye was used as comparison for all imaging studies.

CONCLUSION

These findings support the notion of generalized venous hypertension state in adult eyes with Sturge-Weber syndrome and corroborate previous evidence that the deep capillary plexus acts as a venous outflow system.

Similarities and differences between brain and skin GNAQ p.R183Q driven capillary malformations

Capillary malformations (CM) are congenital vascular irregularities of capillary and venous blood vessels that appear in the skin, leptomeninges of the brain, and the choroid of the eye in the disorder known as Sturge Weber Syndrome (SWS). More common are non-syndromic CM found only in the skin, without brain or ocular involvement. A somatic activating mutation in GNAQ (p.R183Q) is found in ~90% of syndromic and non-syndromic CM specimens and is present in CD31pos endothelial cells isolated from brain and skin CM specimens. Endothelial expression of the GNAQ p.R183Q variant is sufficient to form CM-like vessels in mice. Given the distinct features and functions of blood vessels in the brain versus the skin, we examined the features of CM vessels in both tissues to gain insights into the pathogenesis of CM. Herein, we present morphologic characteristics of CM observed in specimen from brain and skin. The GNAQ p.R183Q variant allelic frequency in each specimen was determined by droplet digital PCR. Sections were stained for endothelial cells, tight junctions, mural cells, and macrophages to assess the endothelium as well as perivascular constituents. CM blood vessels in brain and skin were enlarged, exhibited fibrin leakage and reduced zona occludin-1, and were surrounded by MRC1pos/LYVE1pos macrophages. In contrast, the CMs from brain and skin differ in endothelial sprouting activity and localization of mural cells. These characteristics might be helpful in the development of targeted and/or tissue specific therapies to prevent or reverse non-syndromic and syndromic CM.

MRC1 and LYVE1 expressing macrophages in vascular beds of GNAQ p.R183Q driven capillary malformations in Sturge Weber syndrome

Sturge-Weber syndrome (SWS), a neurocutaneous disorder, is characterized by capillary malformations (CM) in the skin, brain, and eyes. Patients may suffer from seizures, strokes, and glaucoma, and only symptomatic treatment is available. CM are comprised of enlarged vessels with endothelial cells (ECs) and disorganized mural cells. Our recent finding indicated that the R183Q mutation in ECs leads to heightened signaling through phospholipase Cβ3 and protein kinase C, leading to increased angiopoietin-2 (ANGPT2). Furthermore, knockdown of ANGPT2, a crucial mediator of pro-angiogenic signaling, inflammation, and vascular remodeling, in EC-R183Q rescued the enlarged vessel phenotype in vivo. This prompted us to look closer at the microenvironment in CM-affected vascular beds. We analyzed multiple brain histological sections from patients with GNAQ-R183Q CM and found enlarged vessels devoid of mural cells along with increased macrophage-like cells co-expressing MRC1 (CD206, a mannose receptor), CD163 (a scavenger receptor and marker of the monocyte/macrophage lineage), CD68 (a pan macrophage marker), and LYVE1 (a lymphatic marker expressed by some macrophages). These macrophages were not found in non-SWS control brain sections. To investigate the mechanism of increased macrophages in the perivascular environment, we examined THP1 (monocytic/macrophage cell line) cell adhesion to EC-R183Q versus EC-WT under static and laminar flow conditions. First, we observed increased THP1 cell adhesion to EC-R183Q compared to EC-WT under static conditions. Next, using live cell imaging, we found THP1 cell adhesion to EC-R183Q was dramatically increased under laminar flow conditions and could be inhibited by anti-ICAM1. ICAM1, an endothelial cell adhesion molecule required for leukocyte adhesion, was strongly expressed in the endothelium in SWS brain histological sections, suggesting a mechanism for recruitment of macrophages. In conclusion, our findings demonstrate that macrophages are an important component of the perivascular environment in CM suggesting they may contribute to the CM formation and SWS disease progression.

Laser capture microdissection for biomedical research: towards high-throughput, multi-omics, and single-cell resolution

Spatial omics technologies have become powerful methods to provide valuable insights into cells and tissues within a complex context, significantly enhancing our understanding of the intricate and multifaceted biological system. With an increasing focus on spatial heterogeneity, there is a growing need for unbiased, spatially resolved omics technologies. Laser capture microdissection (LCM) is a cutting-edge method for acquiring spatial information that can quickly collect regions of interest (ROIs) from heterogeneous tissues, with resolutions ranging from single cells to cell populations. Thus, LCM has been widely used for studying the cellular and molecular mechanisms of diseases. This review focuses on the differences among four types of commonly used LCM technologies and their applications in omics and disease research. Key attributes of application cases are also highlighted, such as throughput and spatial resolution. In addition, we comprehensively discuss the existing challenges and the great potential of LCM in biomedical research, disease diagnosis, and targeted therapy from the perspective of high-throughput, multi-omics, and single-cell resolution.

Isolated diffuse choroidal hemangioma without systemic symptoms: a case report

BACKGROUND

Sturge-Weber syndrome is a nonhereditary congenital neurocutaneous syndrome characterized by a distinctive facial capillary malformation,neurological abnormalities, and ocular abnormalities such as glaucoma and choroidal hemangioma.It can be divided into different subtypes according to different clinical manifestations. It is rare for a patient to present with isolated difuse choroidal hemangioma and ipsilateral abnormal conjunctival and episcleral vessels without other systemic symptoms.

CASE PRESENTATION

We report a 30-year-old man with isolated diffuse choroidal hemangioma in his right eye without systemic symptoms, such as vascular malformations in the skin or leptomeningeal angiomatosis. The only additional ophthalmic finding was ipsilateral abnormal conjunctival and episcleral vessels without glaucoma. However, there was no evidence of leptomeningeal angiomatosis or port-wine stain on the right side of the face, or glaucoma, which are common clinical manifestations of the Sturge-Weber syndrome (SWS).The absence of these characteristic symptoms did not preclude the diagnosis, and the patient could be diagnosed with a particular subtype of SWS.

CONCLUSIONS

This is a rare case of documented isolated difuse choroidal hemangioma with ipsilateral abnormal conjunctival and episcleral vessels without glaucoma which we think it is belonging to a particular subtype of SWS.In addition to the traditional clinical manifestations, more and more atypical clinical manifestations are also accompanied by SWS, which requires our clinicians to continuously discover and report, so as to help more clinicians understand this disease.

Outcomes of Deep Sclerectomy for Glaucoma Secondary to Sturge-Weber Syndrome

Aims: To report the outcomes and complications of deep sclerectomy in glaucoma secondary to Sturge−Weber syndrome (SWS). Methods: The retrospective case series included patients with SWS and secondary glaucoma who underwent deep sclerectomy at King Abdul Aziz University Hospital, Riyadh, Saudi Arabia between 2000 and 2021. The main outcome measures included intraocular pressure (IOP), the number of antiglaucoma medications, the presence of vision-threatening complications, and the need for further glaucoma surgery to control the IOP. The surgical outcome of each eye was based on the main outcome measures. Results: Twelve eyes of eleven patients were included in the study. The mean follow-up period was 83.00 months (±74.2) (range 1 to 251 months). The IOP and number of antiglaucoma medications decreased significantly from a mean of 28.75 mm Hg (±7.4) and 3.17 (±0.8) to 15.30 mm Hg (±3.5) and 0.3 (±0.7), and 18.83 (±9.3) and 1.67 (±1.7) on the 24th month and the last follow-up visit postoperatively, respectively (p < 0.01 for both). The success rate was 66.6% (8/12), while the failure rate was 33.3% (4/12) because of the uncontrolled IOP where a single repeat glaucoma surgery achieved controlled IOP. One procedure was complicated by choroidal detachment and one by choroidal effusion; both complications were resolved by medical treatments. Conclusions: Deep sclerectomy seems to be an effective treatment modality for controlling IOP and for decreasing the burden of antiglaucoma medications in patients with SWS and secondary glaucoma. Further studies are needed to confirm such a conclusion on larger number of patients with longer follow-up periods.

Choroidal Neovascular Membranes in Retinal and Choroidal Tumors: Origins, Mechanisms, and Effects

Choroidal neovascularizations are historically associated with exudative macular degeneration, nonetheless, they have been observed in nevus, melanoma, osteoma, and hemangioma involving the choroid and retina. This review aimed to elucidate the possible origins of neovascular membranes by examining in vivo and in vitro models compared to real clinical cases. Among the several potential mechanisms examined, particular attention was paid to histologic alterations and molecular cascades. Physical or biochemical resistance to vascular invasion from the choroid offered by Bruch's membrane, the role of fibroblast growth factor 2 and vascular endothelial growth factor, resident or recruited stem-like/progenitor cells, and other angiogenic promoters were taken into account. Even if the exact mechanisms are still partially obscure, experimental models are progressively enhancing our understanding of neovascularization etiology. Choroidal neovascularization (CNV) over melanoma, osteoma, and other tumors is not rare and is not contraindicative of malignancy as previously believed. In addition, CNV may represent a late complication of either benign or malignant choroidal tumors, stressing the importance of a long follow-up.

GNAQ mutations drive port wine birthmark-associated Sturge-Weber syndrome: A review of pathobiology, therapies, and current models

Port-wine birthmarks (PWBs) are caused by somatic, mosaic mutations in the G protein guanine nucleotide binding protein alpha subunit q (GNAQ) and are characterized by the formation of dilated, dysfunctional blood vessels in the dermis, eyes, and/or brain. Cutaneous PWBs can be treated by current dermatologic therapy, like laser intervention, to lighten the lesions and diminish nodules that occur in the lesion. Involvement of the eyes and/or brain can result in serious complications and this variation is termed Sturge-Weber syndrome (SWS). Some of the biggest hurdles preventing development of new therapeutics are unanswered questions regarding disease biology and lack of models for drug screening. In this review, we discuss the current understanding of GNAQ signaling, the standard of care for patients, overlap with other GNAQ-associated or phenotypically similar diseases, as well as deficiencies in current in vivo and in vitro vascular malformation models.

A novel somatic mutation in GNAQ in a capillary malformation provides insight into molecular pathogenesis

Sturge-Weber syndrome (SWS) is a sporadic, congenital, neuro-cutaneous disorder characterized by a mosaic, capillary malformation. SWS and non-syndromic capillary malformations are both caused by a somatic activating mutation in GNAQ encoding the G protein subunit alpha-q protein. The missense mutation R183Q is the sole GNAQ mutation identified thus far in 90% of SWS-associated or isolated capillary malformations. In this study, we sequenced skin biopsies of capillary malformations from 9 patients. We identified the R183Q mutation in nearly all samples, but one sample exhibited a Q209R mutation. This new mutation occurs at the same residue as the constitutively-activating Q209L mutation, commonly seen in tumors. However, Q209R is a rare variant in this gene. To compare the effect of the Q209R mutation on downstream signaling, we performed reporter assays with a GNAQ-responsive reporter co-transfected with either GNAQ WT, R183Q, Q209L, Q209R, or C9X (representing a null allele). Q209L showed the highest reporter activation, with R183Q and Q209R showing significantly lower activation. To determine whether these mutations had similar or different downstream consequences we performed RNA-seq analysis in microvascular endothelial cells (HMEC-1) electroporated with the same GNAQ variants. The R183 and Q209 missense variants caused extensive dysregulation of a broad range of transcripts compared to the WT or null allele, confirming that these are all activating mutations. However, the missense variants exhibited very few differentially expressed genes (DEGs) when compared to each other. These data suggest that these activating GNAQ mutations differ in magnitude of activation but have similar downstream effects.

Orbital Vascular Anomalies: A Nomenclatorial, Etiological, and Nosologic Conundrum

PURPOSE

Vascular anomalies are a heterogeneous group of disorders that frequently present in the periorbital region. They encompass 2 broad entities: vascular tumors, which possess a proliferative endothelium, and vascular malformations, which are basically localized defects of vascular morphogenesis. The primary goal of this review was to address inaccurate or controversial terminology in the oculoplastic literature concerning orbital and periorbital vascular anomalies and to categorize these lesions in an abridged and simplified hierarchical list that adheres as much as possible to the most recent (2018) iteration for the classification of vascular lesions proposed by the International Society for the Study of Vascular Anomalies (ISSVA). The secondary goal of this review was to review and update information regarding the genetic underpinnings of vascular anomalies and the downstream signaling pathways that are subsequently affected as a result of these genetic errors.

METHODS

A literature review was conducted in PubMed, MEDLINE, PubMed Central, National Center for Biotechnology Information Bookshelf, and Embase for several related keywords including "vascular anomalies, vascular malformations, vascular tumors, and cavernous venous malformation," both with and without adding the keywords "eyelid," "orbital," and "periorbital." In addition, a detailed search was conducted for controversial or obsolete keywords like "cavernous hemangioma," "lymphangioma," and "varices," again in their systemic and orbital/periorbital context.

RESULTS

Crucial issues in the 2018 ISSVA classification regarding the proper categorization of orbital vascular anomalies, particularly venous lesions, were critically evaluated and revised, and a regional, simplified, and abridged modification of the ISSVA 2018 classification was proposed.

CONCLUSIONS

Interdisciplinary and intradisciplinary dialogue concerning orbital vascular anomalies is seriously compromised due to the lack of a unanimous agreement on terminology and the absence of a unified classification concept system. The authors recommend that oculoplastic surgeons adopt ISSVA terminology whenever technically possible and scientifically sound. However, they also propose modifying the ISSVA 2018 classification specifically to adapt to the peculiarities of vascular anomalies in the periorbital region. At present, the simplified classification proposed here is a preliminary first step towards managing patients with orbital vascular anomalies with greater diagnostic and therapeutic precision, until such time in the future when the entire genetic makeup of orbital vascular anomalies is more completely elucidated. Optimistically, this could pave the way for a more robust classification and the ultimate therapeutic cure.

Endothelial GNAQ p.R183Q Increases ANGPT2 (Angiopoietin-2) and Drives Formation of Enlarged Blood Vessels

OBJECTIVE

Capillary malformation (CM) occurs sporadically and is associated with Sturge-Weber syndrome. The somatic mosaic mutation in GNAQ (c.548G>A, p.R183Q) is enriched in endothelial cells (ECs) in skin CM and Sturge-Weber syndrome brain CM. Our goal was to investigate how the mutant Gαq (G-protein αq subunit) alters EC signaling and disrupts capillary morphogenesis. Approach and Results: We used lentiviral constructs to express p.R183Q or wild-type GNAQ in normal human endothelial colony forming cells (EC-R183Q and EC-WT, respectively). EC-R183Q constitutively activated PLC (phospholipase C) β3, a downstream effector of Gαq. Activated PLCβ3 was also detected in human CM tissue sections. Bulk RNA sequencing analyses of mutant versus wild-type EC indicated constitutive activation of PKC (protein kinase C), NF-κB (nuclear factor kappa B) and calcineurin signaling in EC-R183Q. Increased expression of downstream targets in these pathways, ANGPT2 (angiopoietin-2) and DSCR (Down syndrome critical region protein) 1.4 were confirmed by quantitative PCR and immunostaining of human CM tissue sections. The Gαq inhibitor YM-254890 as well as siRNA targeted to PLCβ3 reduced mRNA expression levels of these targets in EC-R183Q while the pan-PKC inhibitor AEB071 reduced ANGPT2 but not DSCR1.4. EC-R183Q formed enlarged blood vessels in mice, reminiscent of those found in human CM. shRNA knockdown of ANGPT2 in EC-R183Q normalized the enlarged vessels to sizes comparable those formed by EC-WT.

CONCLUSIONS

Gαq-R183Q, when expressed in ECs, establishes constitutively active PLCβ3 signaling that leads to increased ANGPT2 and a proangiogenic, proinflammatory phenotype. EC-R183Q are sufficient to form enlarged CM-like vessels in mice, and suppression of ANGPT2 prevents the enlargement. Our study provides the first evidence that endothelial Gαq-R183Q is causative for CM and identifies ANGPT2 as a contributor to CM vascular phenotype.

Exploring the choroidal vascular labyrinth and its molecular and structural roles in health and disease

The choroid is a key player in maintaining ocular homeostasis and plays a role in a variety of chorioretinal diseases, many of which are poorly understood. Recent advances in the field of single-cell RNA sequencing have yielded valuable insights into the properties of choroidal endothelial cells (CECs). Here, we review the role of the choroid in various physiological and pathophysiological mechanisms, focusing on the role of CECs. We also discuss new insights regarding the phenotypic properties of CECs, CEC subpopulations, and the value of measuring transcriptomics in primary CEC cultures derived from post-mortem eyes. In addition, we discuss key phenotypic, structural, and functional differences that distinguish CECs from other endothelial cells such as retinal vascular endothelial cells. Understanding the specific clinical and molecular properties of the choroid will shed new light on the pathogenesis of the broad clinical range of chorioretinal diseases such as age-related macular degeneration, central serous chorioretinopathy and other diseases within the pachychoroid spectrum, uveitis, and diabetic choroidopathy. Although our knowledge is still relatively limited with respect to the clinical features and molecular pathways that underlie these chorioretinal diseases, we summarise new approaches and discuss future directions for gaining new insights into these sight-threatening diseases and highlight new therapeutic strategies such as pluripotent stem cell‒based technologies and gene therapy.

Current concepts on diffuse choroidal hemangioma in Sturge Weber syndrome

Background: Diffuse choroidal hemangioma (DCH) is a benign vascular tumor that is characteristically found in the Sturge-Weber syndrome (SWS). Recent genetic discoveries demonstrate that DCH occurs sporadically from an activating mutation in GNAQ at codon R183. Mutations in GNAQ or GNA11 result in dysregulation of the mitogen-activated protein kinase, which influences gene transcription and results in cellular proliferation. DCH may not always be readily detected on routine ophthalmological examination, consequently diagnosis and multidisciplinary referral are often delayed.Purpose: A literature search was performed through April 2020 without a lower date limit. This review will summarize the pathogenesis, diagnosis and management of DCH.Discussion: Multimodal imaging facilitates early detection of the condition. In particular, enhanced depth imaging spectral domain optical coherence tomography enables non-invasive, high-resolution visualization of the choroid to even detect mild choroidal thickening. Management of symptomatic DCH is generally difficult and results in poor visual outcome, thus, treatment is generally unwarranted, unless the hemangioma complicated by serous retinal detachment. The main treatment method is radiation therapy with external beam radiation therapy, proton beam therapy, plaque brachytherapy, and gamma knife surgery where low doses of radiation entail fewer complications. One method of alternative management is with photodynamic therapy that, although less invasive with a lower rate of complications, is not always feasible or effective in cases with extensive exudative retinal detachment.Conclusions: Multimodal ophthalmological imaging facilitates diagnosis of DCH and lifelong surveillance is essential in patients.

Somatic GNAQ R183Q mutation is located within the sclera and episclera in patients with Sturge-Weber syndrome

Aims

To determine the correspondence between GNAQ R183Q (c.548G＞A) mutation in abnormal scleral tissue of patients with Sturge-Weber syndrome (SWS) secondary glaucoma and explore the role of GNAQ R183Q in glaucoma pathogenesis.

Methods

Episcleral tissues were obtained from 8 patients: SWS secondary glaucoma (n=5) and primary congenital glaucoma (PCG, n=3). Scleral tissues were obtained from 7 patients: SWS secondary glaucoma (n=2), PCG (n=1) and juvenile open-angle glaucoma (n=4). GNAQ R183Q mutation was detected in scleral tissue by droplet digital PCR. Tissue sections from SWS were examined by immunohistochemistry to determine the expression of p-ERK.

Results

The GNAQ R183Q mutation was present in 100% of the SWS abnormal sclera. Five cases were SWS patient-derived episcleral tissue, and the mutant allelic frequencies range from 6.9% to 12.5%. The other two were deep scleral tissues and the mutant frequencies were 1.5% and 5.3%. No mutations in GNAQ R183 codon were found in the sclera of PCG and juvenile open-angle glaucoma. Increased expression of p-ERK and p-JNK was detected in the endothelial cells of SWS abnormal scleral blood vessels.

Conclusions

GNAQ R183Q occurred in all abnormal scleral tissue of SWS secondary glaucoma. Increased expression of p-ERK and p-JNK in endothelial cells of blood vessels was detected in the abnormal scleral tissue. This study suggests GNAQ R183Q may regulate episcleral vessels of patients with SWS through abnormal activation of ERK and JNK, providing new genetic evidence of pathogenesis of glaucoma in SWS, and the dysplasia of scleral tissue in anterior segment may be used as an early diagnostic method or treatment targets to prevent the development and progression of glaucoma in patients with SWS.

Targeting primary and metastatic uveal melanoma with a G protein inhibitor

Uveal melanoma (UM) is the most common intraocular tumor in adults. Nearly half of UM patients develop metastatic disease and often succumb within months because effective therapy is lacking. A novel therapeutic approach has been suggested by the discovery that UM cell lines driven by mutant constitutively active Gq or G11 can be targeted by FR900359 (FR) or YM-254890, which are bioavailable, selective inhibitors of the Gq/11/14 subfamily of heterotrimeric G proteins. Here, we have addressed the therapeutic potential of FR for UM. We found that FR inhibited all oncogenic Gq/11 mutants reported in UM. FR arrested growth of all Gq/11-driven UM cell lines tested, but induced apoptosis only in a few. Similarly, FR inhibited growth of, but did not efficiently kill, UM tumor cells from biopsies of primary or metastatic tumors. FR evoked melanocytic redifferentiation of UM tumor cells with low (class 1), but not high (class 2), metastatic potential. FR administered systemically below its LD₅₀ strongly inhibited growth of PDX-derived class 1 and class 2 UM tumors in mouse xenograft models and reduced blood pressure transiently. FR did not regress xenografted UM tumors or significantly affect heart rate, liver function, hematopoiesis, or behavior. These results indicated the existence of a therapeutic window in which FR can be explored for treating UM and potentially other diseases caused by constitutively active Gq/11.

Progressive retinal vessel malformation in a premature infant with Sturge-Weber syndrome: a case report and a literature review of ocular manifestations in Sturge-Weber syndrome

BACKGROUND

Sturge-Weber syndrome is a disorder marked by a distinctive facial capillary malformation, neurological abnormalities, and ocular abnormalities such as glaucoma and choroidal hemangioma.

CASE PRESENTATION

We report a case of progressively formed retinal vessel malformation in a premature male infant with Sturge-Weber syndrome and retinopathy of prematurity, after treatment with intravitreal anti-vascular endothelial growth factor (VEGF). The baby was born at 30 weeks gestation with a nevus flammeus involving his left eyelids and maxillary area. On postmenstrual age week 39, he received intravitreal anti-VEGF. Diffuse choroidal hemangioma became evident at 40 weeks, with the classic "tomato catsup fundus" appearance. These clinical findings characterized Sturge-weber syndrome. He presented with posterior retinal vessel tortuosity and vein-to-vein anastomoses at 44 weeks.

CONCLUSION

This is a rare case of documented progression of retinal vessel malformations in a patient with Sturge-Weber syndrome and retinopathy of prematurity.

Choroidal alterations of Sturge-Weber syndrome secondary glaucoma and non-glaucoma port-wine stain patients distinguished by enhanced depth imaging optical coherence tomography

Background

To evaluate the choroidal changes in Sturge-Weber syndrome (SWS) secondary glaucoma and non-glaucoma port-wine stain (PWS) patients by enhanced depth imaging optical coherence tomography (EDI-OCT).

Methods

SWS and PWS patients who were over 3 years old and treated or screened at our ophthalmology department were included in the study. Baseline demographics, EDI-OCT and fundus photography data were collected from all patients.

Results

Overall, 46 non-glaucoma PWS (NGPWS) patients and 35 SWS secondary glaucoma (SG) patients were included, with mean ages of 16.52 ± 13.63 and 13.94 ± 8.27 years, respectively (p > 0.05). Among these patients 2 exhibited bilateral PWS and unilateral glaucoma. Thus, the two eyes of each patient were divided into NGPWS and SG group, respectively. Twenty-one eyes had choroidal hemangiomas and 7 eyes had excessive thickening of the choroid without choroidal hemangiomas. Choroidal hemangiomas were only observed in ipsilateral eyes of SG patients. The choroidal thicknesses of the ipsilateral and fellow eyes of NGPWS patients were 358.10 ± 117.40 μm (45 eyes) and 288.20 ± 79.04 μm (41 eyes), respectively (p < 0.05). The choroidal thicknesses of the ipsilateral and fellow eyes of SG patients were 511.40 ± 242.10 μm (15 eyes) and 283.90 ± 92.27 μm (29 eyes), respectively (p < 0.05). Significant differences were found between the ipsilateral eyes of SWS and PWS patients (p < 0.05). Six of 13 eyes (46%) with choroidal hemangiomas exhibited post-operative posterior segment complications.

Conclusions

NGPWS and SG patients had a thicker choroid in the ipsilateral eye. The trend was even more pronounced in SG patients. Choroidal hemangiomas were only found in the ipsilateral eyes of SG. In addition, choroidal hemangioma was a risk factor for post-operative posterior segment complications in SWS patients.

Ocular manifestations in phakomatosis pigmentovascularis: Current concepts on pathogenesis, diagnosis, and management

Phakomatosis pigmentovascularis is a rare congenital multisystemic disease with variable manifestations where a vascular malformation of the skin is associated with a pigmentary nevus. Ocular involvement includes glaucoma, choroidal hemangioma, and pigmentary alterations that predispose to uveal melanoma. Diagnosis is made on clinical grounds, although recent advances in molecular genetics have better clarified the etiopathogenesis of the condition. The advent of improved imaging techniques such as enhanced depth imaging spectral domain optical coherence tomography has provided new insight into the ocular alterations, enabling better follow-up of patients. We review the ophthalmic manifestations of the disease with an update on etiopathogenesis and current management strategies.

A somatic missense mutation in GNAQ causes capillary malformation

PURPOSE OF REVIEW

Capillary malformations, the most common type of vascular malformation, are caused by a somatic mosaic mutation in GNAQ, which encodes the Gαq subunit of heterotrimeric G-proteins. How the single amino acid change - predicted to activate Gαq - causes capillary malformations is not known but recent advances are helping to unravel the mechanisms.

RECENT FINDINGS

The GNAQ R183Q mutation is present not only in endothelial cells isolated from skin and brain capillary malformations but also in brain tissue underlying the capillary malformation, raising questions about the origin of capillary malformation-causing cells. Insights from computational analyses shed light on the mechanisms of constitutive activation and new basic science shows Gαq plays roles in sensing shear stress and in regulating cerebral blood flow.

SUMMARY

Several studies confirm the GNAQ R183Q mutation in 90% of nonsyndromic and Sturge-Weber syndrome (SWS) capillary malformations. The mutation is enriched in endothelial cells and blood vessels isolated from skin, brain, and choroidal capillary malformations, but whether the mutation resides in other cell types must be determined. Further, the mechanisms by which the R183Q mutation alters microvascular architecture and blood flow must be uncovered to develop new treatment strategies for SWS in particular, a devastating disease for which there is no cure.

Incidence of Sturge-Weber syndrome and associated ocular involvement in Olmsted County, Minnesota, United States

Background: Sturge-Weber syndrome (SWS) is a rare sporadic syndrome characterized by nevus flammeus (port-wine stain, PWS) in the trigeminal nerve distribution, diffuse choroidal hemangioma, and brain leptomeningeal hemangioma. We are unaware of previous reports of SWS incidence in the United States. This study investigated SWS incidence and associated ocular involvement in Olmsted County, Minnesota.Materials and methods: The Rochester Epidemiology Project database was used to identify SWS cases from January 1, 2000-December 31, 2017. Incidence of SWS was calculated using the Olmsted County census population. A literature review of studies investigating SWS-associated ocular involvement was also performed.Results: There were 13 patients with SWS in Olmsted County classified as type 1 (31%) or type 2 (69%). Age and sex-adjusted incidence of SWS was 0.19/100,000/year. Race was predominantly Caucasian (85%), with sex female (69%) or male (31%). All patients had PWS, mostly with unilateral distribution in the V1 and/or V2 region (85%). Two cases (15%) had associated Klippel-Trenaunay syndrome. The most common ocular features included: dilated episcleral vessels (46%), glaucoma (46%), retinal detachment (23%), DCH (7.7%), strabismus (31%), and refractive error (38%). PWS in the V1 distribution was associated with all cases of glaucoma, DCH, and neurological involvement. Severe visual impairment (>0.6 LogMAR, Snellen equivalent ≤20/100) was found in (23%) at final follow-up, and one patient (8%) required enucleation for uncontrolled glaucoma.Conclusions: SWS affects approximately 0.19/100,000/year in Olmsted County. Early diagnosis, intervention, lifelong follow-up, and multidisciplinary approach should be used to optimize systemic and ocular outcomes.

GNAQ Q209R Mutations Are Highly Specific for Circumscribed Choroidal Hemangioma

Several tumors, including uveal melanoma, show somatic mutations of GNAQ/GNA11. Circumscribed choroidal hemangioma is a benign tumor that becomes symptomatic in adulthood. In some patients, morphologic examination of biopsies is required for differential diagnosis between amelanotic choroidal melanoma and circumscribed choroidal hemangioma. Here, we report the results of GNAQ/GNA11 mutation analysis in samples from circumscribed choroidal hemangioma. Deep amplicon sequencing (Illumina MiSeq, San Diego, CA, USA) of positions R183 and Q209 of GNAQ and GNA11 in tissue samples from 33 patients with histologically diagnosed circumscribed choroidal hemangioma. All patients underwent biopsy or enucleation at our clinic between 2008 and 2018. To enable detection of variant alleles at low fractions, read depth exceeded 15,000-fold. DNA for genetic analysis was prepared from either snap-frozen (n = 22) or FFPE (n = 11) tissue samples. Samples from 28/33 patients (85%) showed a somatic missense mutation of GNAQ (c.626 A > G) predicted to result in p.Q209R. Variant allele fraction was variable (range 2.3% to 28%). Variants of GNAQ resulting in p.Q209 are characteristic for circumscribed choroidal hemangiomas. It appears that the GNAQ mutation spectrum in this tumor is narrow, possibly restricted to p.Q209R. Moreover, the spectrum is distinct from that of uveal melanoma, in which alterations resulting in p.Q209R are very rare.

Circumscribed choroidal hemangioma: Clinical features and outcomes by age category in 458 cases

Purpose

To investigate features and outcomes of circumscribed choroidal hemangioma by patient age.

Methods

Retrospective review of circumscribed choroidal hemangioma from 3/29/1967–6/4/2018 based on age at presentation (≤20 vs. >20–50 vs. >50 years).

Results

There were 458 circumscribed choroidal hemangiomas diagnosed at mean age (13 vs. 41 vs. 64 years, p < 0.001). The youngest age group had worse presenting visual acuity (20/400 vs. 20/150 vs. 20/100, p < 0.001), larger tumor basal diameter (13.5 vs. 6.6 vs. 6.2, p < 0.001), greater tumor thickness (5.8 vs. 3.1 vs. 2.9, p < 0.001), closer distance to foveola (0.5 vs. 1.4 vs. 1.2, p = 0.03), and greater extent of subretinal fluid (4 quadrants, 26% vs. 8% vs. 2%, p < 0.001). The youngest patients were less likely to be treated with primary observation (39% vs. 39% vs. 56%) or photodynamic therapy (10% vs. 27% vs. 22%) and more likely to be treated with plaque radiotherapy (26% vs. 6% vs. 3%) or external beam radiotherapy (13% vs. 1% vs. 0%) (p < 0.001). The youngest patients required greater total number of treatments (mean 4 vs. 2 vs. 1, p < 0.001). At mean follow-up (44 vs. 68 vs. 60 months, p = 0.37), the youngest patients had worse visual acuity (20/400 vs. 20/200 vs. 20/100, p = 0.03), but no difference in visual acuity loss of 3 or more Snellen lines (27% vs. 13% vs. 16%, p = 0.55).

Conclusion

Younger patients (≤20 years) with circumscribed choroidal hemangioma present with worse visual acuity and larger, more posterior tumors. Future studies are needed to improve early detection and treatment for this subgroup of patients.

GNAQ Mutations in Diffuse and Solitary Choroidal Hemangiomas

PURPOSE

GNAQ mutations have been identified in port wine stains (both syndromic and nonsyndromic) and melanocytic ocular neoplasms. This study investigates the presence of GNAQ mutations in diffuse (those associated with Sturge-Weber syndrome [SWS]) and solitary choroidal hemangiomas.

PARTICIPANTS

Tissue from 11 patients with the following diagnoses: port wine stain (n = 3), diffuse choroidal hemangioma (n = 1), solitary choroidal hemangioma (n = 6), and choroidal nevus (n = 1).

METHODS

Ten specimens were interrogated with Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets, a hybridization capture-based next-generation sequencing assay for targeted deep sequencing of all exons and selected introns of 468 key cancer genes in formalin-fixed, paraffin-embedded tumors. Digital polymerase chain reaction was used to detect GNAQ Q209 mutation in 1 specimen.

MAIN OUTCOME MEASURES

Detection of GNAQ codon-specific mutation.

RESULTS

Activating somatic GNAQ mutations (c.547C > T; p.Arg183Cys) were found in 100% (3 of 3) of the port wine stain and in the diffuse choroidal hemangioma. Somatic GNAQ mutations (c.626A > T; p.Gln209Leu) were found in 100% (6 of 6) of the solitary choroidal hemangiomas and (c.626A > C; p.Gln209Pro) in the choroidal nevus.

CONCLUSIONS

GNAQ mutations occur in both diffuse and solitary hemangiomas, although at distinct codons. An R183 codon is mutant in diffuse choroidal hemangiomas, consistent with other Sturge-Weber vascular malformations. By contrast, solitary choroidal hemangiomas have mutations in the Q209 codon, similar to other intraocular melanocytic neoplasms.