Prenatal Clinical Findings in RASA1-Related Capillary Malformation-Arteriovenous Malformation Syndrome.

Pathogenic variants in RASA1 are typically associated with a clinical condition called "capillary malformation-arteriovenous malformation" (CM-AVM) syndrome, an autosomal dominant genetic disease characterized by a broad phenotypic variability, even within families. In CM-AVM syndrome, multifocal capillary and arteriovenous malformations are mainly localized in the central nervous system, spine and skin. Although CM-AVM syndrome has been widely described in the literature, only 21 cases with prenatal onset of clinical features have been reported thus far. Here, we report four pediatric cases of molecularly confirmed CM-AVM syndrome which manifested during the prenatal period. Polyhydramnios, non-immune hydrops fetalis and chylothorax are only a few possible aspects of this condition, but a correct interpretation of these prenatal signs is essential due to the possible fatal consequences of unrecognized encephalic and thoracoabdominal deep vascular malformations in newborns and in family members carrying the same RASA1 variant.

Pathogenesis of Port-Wine Stains: Directions for Future Therapies.

Port-wine stains (PWSs) are congenital vascular malformations that involve the skin and mucosa. To date, the mechanisms underlying the pathogenesis and progression of PWSs are yet to be clearly elucidated. The potential reasons for dilated vessels are as follows: (1) somatic GNAQ (R183Q) mutations that form enlarged capillary malformation-like vessels through angiopoietin-2, (2) decreased perivascular nerve elements, (3) the coexistence of Eph receptor B1 and ephrin B2, and (4) the deficiency of αSMA expression in pericytes. In addition, ERK, c-JNK, P70S6K, AKT, PI3K, and PKC are assumed to be involved in PWS development. Although pulsed-dye laser (PDL) remains the gold standard for treating PWSs, the recurrence rate is high. Topical drugs, including imiquimod, axitinib, and rapamycin, combined with PDL treatments, are expected to alter the recurrence rate and reduce the number of PDL sessions for PWSs. For the deep vascular plexus, photosensitizers or photothermal transduction agents encapsulated by nanocarriers conjugated to surface markers (CD133/CD166/VEGFR-2) possess a promising therapeutic potential in photodynamic therapy or photothermal therapy for PWSs. The pathogenesis, progression, and treatment of PWSs should be extensively investigated.

Capillary malformation-arteriovenous malformation syndrome associated with basilar artery aneurysm.

A 23-day-old boy with prenatal diagnosis of basilar artery aneurysm presented with multiple congenital red patches consistent with capillary malformations. Genetic testing confirmed the presence of a heterozygous pathogenic variant of the RASA1 gene, confirming the diagnosis of capillary malformation-arteriovenous malformation (CM-AVM) syndrome. This case illustrates an atypical presentation of the RASA1 associated CM-AVM syndrome, with the intracranial vascular malformation diagnosis preceding the identification of the skin lesions. Arterial aneurysms have been associated with CM-AVM syndrome in rare instances but to our knowledge this is the first reported case of an aneurysm of the basilar artery.

Capillary Malformation-arteriovenous Malformation Type 2: A Case Report and Review.

Capillary malformation-arteriovenous malformation syndrome is a rare genodermatosis with cutaneous capillary malformations and a risk of associated fast-flow malformations. We describe here a four-generation family with a novel heterozygous pathogenic variant in the EPHB4 gene (NM_004444.5 (EPHB4): c.2224G>C, p.(Ala742Pro)). A review of the literature retrieved 127 patients with capillary malformation-arteriovenous malformation syndrome and confirmed variants in EPHB4. Multiple capillary malformations were present in 114 (89.76%) patients, and 12 (9.44%) patients had a solitary capillary malformation. Arteriovenous malformations/fistulas were present in 23 (18.1%) patients, and were located within the central nervous system in 5 (3.9%) patients. Not all papers included description of epistaxis. Telangiectasias were reported in 28 (22%) patients, and Bier spots were described in 20 (15.7%) patients. The clinical characteristics of capillary malformation-arteriovenous malformation syndrome are diverse and often discrete, which can make it difficult to distinguish capillary malformation-arteriovenous malformation syndrome from hereditary haemorrhagic telangiectasia.

Coexistence of RASA1 and COL4A2 variants caused pial arteriovenous fistula (AVF) in a patient with capillary malformation-arteriovenous malformation.

Pial arteriovenous fistulas (AVFs) are rare vascular lesions; their exact pathophysiology is largely unknown. Pial AVFs have been reported to develop within capillary malformation-arteriovenous malformation (CM-AVM); however, only a few cases have been reported. Variants in the RASA1 gene have been reported as a cause of CM-AVM. We report the case of an adult patient with pial AVF, who carried variants in the RASA1 and COL4A2 genes. The patient in the current report was likely to have been affected by CM-AVM and the RASA1 variant seemed to be the primary factor in the pathogenesis of pial AVF. However, COL4A2 may have also contributed to the development of pial AVF because the COL4A2 and RASA1 variants have a common pathophysiology, wherein the patient develops lesions due to collagen type IV deficiency.

Characterization of vascular stains associated with high flow.

BACKGROUND: High-flow vascular stains (HFVS) are lesions that have the appearance of capillary malformations/port wine stains but are associated with increased arterial flow. OBJECTIVE: To identify features of HFVS that differentiate them from typical "slow-flow" port wine stains. METHODS: Retrospective multicenter cohort study of HFVS evaluated across 7 centers was conducted. HFVS were characterized by clinical features (warmth, thrill, rapid capillary refill), radiologic findings (fast flow), or mutations associated with capillary malformation-arteriovenous malformation syndrome. Investigators reviewed photographs. RESULTS: The study reviewed 70 patients with HFVS (47 multifocal and 23 solitary). Most were flat (77%), warm to the touch (60%), and red or pink-red in color (35%), with heterogeneous color saturation (73%) and well-defined borders (71%). Regional soft tissue swelling/overgrowth was common (47%). Head and neck location was most common (38%). Among 34 HFVS with photographic review over time, all demonstrated changes in appearance. LIMITATIONS: Retrospective design, recall bias, lack of standardized time points or visual analog scale, and image variability. CONCLUSION: Heterogeneity of stain color saturation, warmth to touch, peripheral pallor, and overgrowth/soft tissue swelling help distinguish HFVS from port wine stains. Darkening of color and increased border demarcation may develop over time. These findings raise suspicion for HFVS and provide an indication to assess for extracutaneous involvement.

Capillary malformation-arteriovenous malformation syndrome: a multicentre study.

BACKGROUND: Capillary malformation-arteriovenous malformation (CM-AVM) syndrome is a rare syndrome with characteristic skin lesions that are associated with fast-flow vascular malformations (FFVMs) in one-third of patients. Few case series have been described, and none in Spain. AIM: To identify the prevalence of dermatological parameters, FFVMs and associated features in a large series of patients with CM-AVM. METHODS: We conducted an observational study of patients with CM-AVM syndrome diagnosed in 15 Spanish hospitals over 3 years. The main clinical, radiological, genetic findings and associated diseases were analysed. RESULTS: In total, 64 patients were assessed. In 26.5% of cases, the diagnosis was incidental. In 75% of patients, there was one significantly larger macule, which we termed the 'herald patch'. FFVMs were detected in 34% of the patients, with 30% located on the skin, 7.8% in the brain and in 1.5% in the spine. There was a positive family history in 65% of the 64 patients. Genetic analysis was performed for RASA1 mutations in 57 patients, of whom 42 (73%) had a positive result. All 4 patients tested for EPHB4 mutations had a positive result. No tumour lesions were detected in the series, except for five infantile haemangiomas. CONCLUSIONS: Our data on clinical lesions, associated FFVM, family history and genetics are similar to those previously published in the literature. An extensive data analysis failed to demonstrate any statistically significant association between the presence of an FFVM and any clinical, familial or genetic parameter that could predict its onset, although a link between the presence of a herald patch on the midline face and the presence of a brain FFVM was observed. We did not detect any genotype-phenotype correlation.

RhoA activation-mediated vascular permeability in capillary malformation-arteriovenous malformation syndrome: a hypothesis.

Capillary malformation-arteriovenous malformation (CM-AVM) syndrome is a class of capillary anomalies that are associated with arteriovenous malformations and arteriovenous fistulas, which carry a risk of hemorrhages. There are no broadly effective pharmacological therapies currently available. Most CM-AVMs are associated with a loss of RASA1, resulting in constitutive activation of RAS signaling. However, protein interaction analysis revealed that RASA1 forms a complex with Rho GTPase-activating protein (RhoGAP), a negative regulator of RhoA signaling. Herein, we propose that loss of RASA1 function results in constitutive activation of RhoA signaling in endothelial cells, resulting in enhanced vascular permeability. Therefore, strategies aimed at curtailing RhoA activity should be tested as an adjunctive therapeutic approach in cell culture studies and animal models of RASA1 deficiency.

RASopathies: A significant cause of polyhydramnios?

OBJECTIVE: The aim of the study is to determine the prevalence of RASopathies in a polyhydramnios cohort selected by postnatal medical genetics evaluation. METHODS: In this retrospective study, we reviewed 622 pregnancies with polyhydramnios seen at Lucile Packard Children's Hospital between 2008 and 2017. The findings from 131 cases evaluated by Medical Genetics were included in our final analysis. Genetic testing information was extracted to determine the rate of chromosomal or single gene conditions focusing on the RASopathies. Additional variables collected were: maternal characteristics, ultrasound findings, and the severity and timing of diagnosis of polyhydramnios. RESULTS: Postnatal genetic testing or clinical examination identified a genetic disorder in 63 (48.1%) cases, more than half (n = 33) of which had a single gene condition. Postnatal testing revealed an underlying RASopathy in 15 (11.5%) cases. An underlying RASopathy was significantly associated with the severity and timing of polyhydramnios (p < 0.05). CONCLUSION: Focusing on a selected cohort postnatally evaluated by Medical Genetics, our study identified a chromosomal or genetic disorder in almost half of pregnancies complicated by polyhydramnios. Specifically, an underlying RASopathy was found in 11.5% of cases with 13/15 of these cases having additional ultrasound findings.

Unilateral and segmental distribution of facial erythema: is it a real port-wine stain?

Capillary malformation-arteriovenous malformations (CM-AVMs) caused by a RASA-1 or EPHB4 mutation are characterized as hereditary sporadic or multifocal capillary malformations (CMs), associated with potential fast-flow vascular anomalies underlying erythema lesions. Because of the similar phenotype, CM-AVMs should be considered in the differential diagnosis of isolated CMs as well as other disorders with an erythema phenotype, such as hereditary hemorrhagic telangiectasia (HHT).Herein, we report a male patient with facial erythema. Red lesions were located in the V1 region of his left face, the V2 and V3 regions on his right side, and the nasal back. The patient was initially thought to have PWSs because of the unilateral and segmental distribution of his red facial lesions. In contrast to a previous diagnosis, we diagnosed the child with capillary malformation-arteriovenous malformation type 2 (CM-AVM2) based on a family history of erythema, the results of physical examination and ultrasound raising potential fast-flow lesions, and a genetic study revealing a germline EPHB4 mutation. This study emphasizes the importance of differential diagnosis for PWS and CM-AVM. A single clinical diagnosis can be limited, and molecular diagnosis is recommended to provide more information for the evaluation of the potential risk of fast-flow lesions underlying erythema lesions if necessary.

[Neonatal capillary malformation-arteriovenous malformation complicated with acute heart failure: a case report and literature review].

Objective: To study the clinical characteristics and current treatment of neonatal capillary malformation-arteriovenous malformation (CM-AVM). Methods: Clinical data of a newborn diagnosed with neonatal CM-AVM caused by RASA1 gene variation admitted to Shanghai Children's Medical Center Affiliated to Shanghai Jiao Tong University School of Medicine was retrospectively analyzed, and related literature was reviewed. Databases of CNKI, WanFang, and Pubmed were searched for the literature from January 1, 2009 to December 31, 2018, with the keywords of "capillary malformation-arteriovenous malformation" "neonatal" and "RASA1 gene" . The clinical features of neonatal CM-AVM were summarized. Results: A one-day-old male infant was admitted to hospital due to swelling of both lower extremities with erythema with elevated skin temperature, who later presented with acute heart failure on the third day of hospitalization. A giant spinal arteriovenous fistula was identified by abdominal contrast-enhanced computed tomography and digital subtraction angiography. After surgical ligation of two feeding arteries, both heart failure and lower limb swelling improved. Genetic testing detected a novel paternal heterozygous variation of RASA1 gene. Digital subtraction angiography showed that spinal AVM still exist at the age of 6 months, but the heart function was good. A total of 4 cases of neonatal CM-AVM had been reported in 3 papers. According to these 5 cases, the clinical manifestations of neonatal CM-AVM were summarized: multiple dermal capillary malformation (5 cases), limb swelling or head circumference enlargement (5 cases), arteriovenous malformation (5 cases), congestive heart failure (4 cases) and positive family history (5 cases). Conclusions: CM-AVM is a rare disease and could present early in neonatal period. Capillary malformation and congestive heart failure of unknown origin in infants may indicate the existence of CM-AVM, and timely imaging and genetic test will help early diagnosis and treatment, and improve prognosis.

The Master of Puppets: Pleiotropy of PDGFRB and its Relationship to Multiple Diseases.

The platelet-derived growth factor receptor beta (PDGFRB) gene is involved in proliferative and developmental processes in mammals. Variations in this gene lead to several different syndromic conditions, such as infantile myofibromatosis I, sporadic port-wine stain, primary familial brain calcification, and the Penttinen and overgrowth syndromes. Our objective was to investigate PDGFRB's genetic relationship to clinical conditions and evaluate the protein interactions using GeneNetwork, GeneMANIA, and STRING network databases. We have evidenced the gene's pleiotropy through its many connections and its link to syndromic conditions. Therefore, PDGFRB may be an important therapeutic target for treating such conditions.

RASA1 mosaic mutations in patients with capillary malformation-arteriovenous malformation.

BACKGROUND: Capillary malformation-arteriovenous malformation is an autosomal dominant disorder, characterised by capillary malformations and increased risk of fast-flow vascular malformations, caused by loss-of-function mutations in the RASA1 or EPHB4 genes. Around 25% of the patients do not seem to carry a germline mutation in either one of these two genes. Even if other genes could be involved, some individuals may have mutations in the known genes that escaped detection by less sensitive techniques. We tested the hypothesis that mosaic mutations could explain some of previously negative cases. METHODS: DNA was extracted from peripheral blood lymphocytes, saliva or vascular malformation tissues from four patients. RASA1 and EPHB4 coding regions and exon/intron boundaries were analysed by targeted custom gene panel sequencing. A second panel and/or Sanger sequencing were used to confirm the identified mutations. RESULTS: Four distinct mosaic RASA1 mutations, with an allele frequency ranging from 3% to 25%, were identified in four index patients with classical capillary malformation-arteriovenous malformation phenotype. Three mutations were known, one was novel. In one patient, a somatic second hit was also identified. One index case had three affected children, illustrating that the mosaicism was also present in the germline. CONCLUSION: This study shows that RASA1 mosaic mutations can cause capillary malformation-arteriovenous malformation. Thus, highly sensitive sequencing techniques should be considered as diagnostic tools, especially for patients with no family history. Even low-level mosaicism can cause the classical phenotype and increased risk for offspring. In addition, our study further supports the second-hit pathophysiological mechanism to explain the multifocality of vascular lesions in this disorder.

Port-wine stains associated with large vestibular aqueduct syndrome caused by mutations in GNAQ and SLC26A4 genes: A case report.

Port-wine stains (PWS) are capillary malformations associated with mutation in the GNAQ (NM_000441.1) gene. Large vestibular aqueduct syndrome (LVAS), caused by mutation in the SLC26A4 (NM_002072) gene, is an inner ear malformation that can lead to hearing loss. To our knowledge, LVAS in PWS patients has never been reported. Here, we describe a case of a 9-year-old female patient diagnosed with PWS on the face and neck, coexisting with large vestibular aqueduct syndrome. Further analyses revealed a somatic mutation in GNAQ and a compound heterozygous mutation in the SLC26A4 gene. Some PWS patients have associated abnormalities, such as glaucoma and choroidal hemangioma, leptomeningeal angiomas and atrophy or hypertrophy of bone and soft tissue. We present here the first case that reveals the possibility that capillary malformations are associated with inner ear malformation. More case reports and further studies are needed to determine whether these conditions coexist in other patients.

Atypical capillary malformations with subsequent diplegia: A difficult case of capillary malformation-arteriovenous malformation syndrome.

Capillary malformation-arteriovenous malformation syndrome (CM-AVM) is a rare condition associated with mutations in the genes RASA1 and EPHB4. We present a challenging case of CM-AVM in a 17-month-old boy with permanent diplegia from an undiagnosed arteriovenous malformation underlying a large atypical capillary malformation over the lower thoracic spine. This case demonstrates that clinicians should have a low threshold for neuroimaging in the context of new neurologic symptoms in patients with atypical capillary malformations.

Phenotypic association of presence of a somatic GNAQ mutation with port-wine stain distribution in capillary malformation.

BACKGROUND: A somatic mutation of GNAQ (c.548G>A, p.Arg183Gln) plays a key role in capillary malformation development. The present study aimed to evaluate clinical manifestations of port-win stain (PWS) associated with this genetic mutation. METHODS: Skin tissue was obtained from 70 patients with capillary malformation who had been treated with excision for lesions. Droplet digital polymerase chain reaction was used to quantify the abundance of cells with the GNAQ mutation. RESULTS: The GNAQ mutation was found in 50 patients. Patients with lesions involving upper facial region, which included forehead, eyebrow, and upper eyelid, showed a significantly higher rate of positive GNAQ mutation than those not involving it. Cases with facial PWS involving all three facial regions (upper, middle, and lower) showed significantly higher positive rate of GNAQ mutation compared to those involving one or two. CONCLUSIONS: Presence of the somatic mutation GNAQ p.Arg183Gln might be associated with clinical manifestations of PWS.

Novel RASA1 mutations in Japanese pedigrees with capillary malformation-arteriovenous malformation.

Capillary malformation-arteriovenous malformation (CM-AVM, MIM#608354) is a rare autosomal dominant disorder characterized by multiple cutaneous capillary malformations co-occurring with fast-flow vascular anomalies, such as arteriovenous malformation or fistula. Despite the identification of RASA1 as the first causative gene in Western patients with CM-AVM, there have been no literature reports of Japanese patients with this gene mutation. We herein report two Japanese pedigrees harboring multiple affected members with CM-AVM. Whole-exome sequencing in the two probands identified novel heterozygous mutations in RASA1, which were co-segregated with the disease in each family and were not reported in large-scale sequencing databases. One was a frameshift mutation and the other a splice-site mutation causing aberrant splicing, confirmed by a minigene assay. There were no other genes commonly disrupted among these probands. RASA1 was a major causative gene even in Japanese patients with CM-AVM, although obvious locus heterogeneity was known for this disease.