The genetics of vascular anomalies:

Reconstructive Venous Surgery in Vascular Malformation: Palma Operation - A Case Report

Congenital morphological disorders of the vascular bed, especially located on the main arteries and veins of the extremities, can cause chronic venous insufficiency and venous claudication, creating exacerbated symptoms for the patient and which require intervention. In cases where interventional radiology is insufficient, surgical approaches should be prioritized. Sixty-five years old male patient admitted to our clinic with increased bilateral lower extremity swelling which revealed to be chronic venous insufficiency secondary to congenital disorders. Sapheno-femoral veno-venous bypass (Palma operation) was performed, and patient was discharged on post-operative day 15 without further complaints. Palma Operation is an effective surgical treatment option in venous malformations of lower extremity where interventional radiology is not sufficient.

Basic Knowledge and Overview of Brain AVMs

Brain arteriovenous malformations (AVMs) are intricate networks of blood vessels in which arteries connect directly to veins, bypassing the capillary system. This aberration can lead to serious neurological manifestations, including seizures, headaches, and hemorrhagic strokes. The embryonic development of AVMs implicates possible disruptions in arteriovenous differentiation during angiogenesis, improper regression of the primary capillary plexus, or the retention of fetal vasculature as contributing factors. Additionally, genetic mutations and environmental influences during pregnancy may facilitate AVM formation, with identified mutations in genes such as endoglin, activin receptor-like kinase 1, SMAD family member 4, and RAS p21 protein activator 1 disrupting vascular development. Such mutations are associated with conditions like hereditary hemorrhagic telangiectasia and capillary malformation-arteriovenous malformation syndrome, thus highlighting the essential role of genetic counseling in AVM management. This review underscores the importance of a deep comprehension of the embryological and genetic foundations of AVMs to refine diagnostic, therapeutic, and prognostic approaches. The paper advocates for advanced research on intervention strategies and emphasizes the significance of a genetics-focused approach in the clinical management of AVMs.

Infantile Hemangioma: A Common Lesion in a Vulnerable Population

Infantile hemangioma (IH) is important to all dentists, particularly dentists providing services to pediatric populations, because significant morbidity and mortality can occur from vascular lesions in children. Specialists of the oral cavity have the responsibility to identify patients with IH, a lesion that could be potentially life threatening. We present a case of IH and will provide a narrative review of the most recent literature. We discuss the diagnosis, risk stratification, treatment, complications, and impact on routine dental procedures. A proper diagnosis is crucial as oral and perioral IH are considered high-risk due to the increased risk of ulceration and feeding impairment. Referral to a hemangioma specialist for comprehensive team treatment is optimal. The natural history of IH consists of a long proliferative phase, which manifests as clinically visible growth. As a result of early encounters with patients, the pediatric dentist may often be considered the primary care provider.

Genetic Basis and Therapies for Vascular Anomalies

Vascular and lymphatic malformations represent a challenge for clinicians. The identification of inherited and somatic mutations in important signaling pathways, including the PI3K (phosphoinositide 3-kinase)/AKT (protein kinase B)/mTOR (mammalian target of rapamycin), RAS (rat sarcoma)/RAF (rapidly accelerated fibrosarcoma)/MEK (mitogen-activated protein kinase kinase)/ERK (extracellular signal-regulated kinases), HGF (hepatocyte growth factor)/c-Met (hepatocyte growth factor receptor), and VEGF (vascular endothelial growth factor) A/VEGFR (vascular endothelial growth factor receptor) 2 cascades has led to the evaluation of tailored strategies with preexisting cancer drugs that interfere with these signaling pathways. The era of theranostics has started for the treatment of vascular anomalies. Registration: URL: https://www.clinicaltrialsregister.eu; Unique identifier: 2015-001703-32.

Prioritization of genes involved in endothelial cell apoptosis by their implication in lymphedema using an analysis of associative gene networks with ANDSystem

BACKGROUND

Currently, more than 150 million people worldwide suffer from lymphedema. It is a chronic progressive disease characterized by high-protein edema of various parts of the body due to defects in lymphatic drainage. Molecular-genetic mechanisms of the disease are still poorly understood. Beginning of a clinical manifestation of primary lymphedema in middle age and the development of secondary lymphedema after treatment of breast cancer can be genetically determined. Disruption of endothelial cell apoptosis can be considered as one of the factors contributing to the development of lymphedema. However, a study of the relationship between genes associated with lymphedema and genes involved in endothelial apoptosis, in the associative gene network was not previously conducted.

METHODS

In the current work, we used well-known methods (ToppGene and Endeavour), as well as methods previously developed by us, to prioritize genes involved in endothelial apoptosis and to find potential participants of molecular-genetic mechanisms of lymphedema among them. Original methods of prioritization took into account the overrepresented Gene Ontology biological processes, the centrality of vertices in the associative gene network, describing the interactions of endothelial apoptosis genes with genes associated with lymphedema, and the association of the analyzed genes with diseases that are comorbid to lymphedema.

RESULTS

An assessment of the quality of prioritization was performed using criteria, which involved an analysis of the enrichment of the top-most priority genes by genes, which are known to have simultaneous interactions with lymphedema and endothelial cell apoptosis, as well as by genes differentially expressed in murine model of lymphedema. In particular, among genes involved in endothelial apoptosis, KDR, TNF, TEK, BMPR2, SERPINE1, IL10, CD40LG, CCL2, FASLG and ABL1 had the highest priority. The identified priority genes can be considered as candidates for genotyping in the studies involving the search for associations with lymphedema.

CONCLUSIONS

Analysis of interactions of these genes in the associative gene network of lymphedema can improve understanding of mechanisms of interaction between endothelial apoptosis and lymphangiogenesis, and shed light on the role of disturbance of these processes in the development of edema, chronic inflammation and connective tissue transformation during the progression of the disease.

RASA1 mutation in a family with capillary malformation-arteriovenous malformation syndrome: A discussion of the differential diagnosis

We describe a family who presented with several scattered, vascular, cutaneous lesions and was found to have a novel mutation in RASA1, diagnostic of capillary malformation-arteriovenous malformation syndrome. Our patient was initially given a presumptive clinical diagnosis of hereditary hemorrhagic telangiectasia. Capillary malformation-arteriovenous malformation syndrome shares several features with hereditary hemorrhagic telangiectasia and hereditary benign telangiectasia, but it can be distinguished clinically according to its morphologic appearance and distribution of cutaneous vascular lesions, the presence of internal fast-flow lesions, and genetic analysis.

Inheritance Patterns of Infantile Hemangioma

BACKGROUND AND OBJECTIVE

Infantile hemangioma (IH) includes, among its other risk factors, familial clustering, but a definitive understanding of IH's inheritance model and genetic basis is lacking. Our objective was to collect IH pedigrees in Finland, to study the inheritance patterns of IH within these families, and to analyze the characteristics of familial IHs.

METHODS

We identified 185 patients with IH who visited our vascular anomaly clinic between 2004 and 2007. Based on hospital records and a questionnaire sent to these patients and their families, IH characteristics and family history of IH were studied. We compared characteristics between patients with positive (familial) and negative (sporadic) IH family history. Families with positive IH family history were further interviewed for extended pedigree data.

RESULTS

One-third of our IH cohort's families reported a family history positive for IH, with IH characteristics and perinatal data between the familial and sporadic cases being similar. IH patients with affected first-degree relatives reported higher long-term discomfort rates than the sporadic cases. Of the 40 families interviewed, 11 included ≥4 IH-affected family members; these were most commonly first-degree relatives (63%). Segregation patterns match with autosomal dominant inheritance with an incomplete penetrance or maternal transmission. We also present a case of monozygotic twins that manifest identical IHs.

CONCLUSIONS

Based on this large number of IH pedigrees, we suggest at least 2 possible mechanisms of inheritance: autosomal dominant and maternal transmission. This study highlights the need for additional genetic studies to define inheritance of this common disease.

Laser applications for benign oral lesions

BACKGROUND AND OBJECTIVE

Different subspecialists treat benign intraoral lesions using various approaches including surgical excision, medical therapy, sclerotherapy, and laser photocoagulation. The goal of this study was to establish whether lasers could effectively target and destroy oral lesions containing endogenous chromophores, while minimizing injury to unaffected adjacent tissues and critical structures.

MATERIALS AND METHODS

This retrospective study involved 26 cases of benign oral lesions, both vascular and pigmented, which were addressed by means of selective laser treatment. Pathologies were port-wine stains, hereditary hemorragic teleangectasia, hemangiomas, venous and arteriovenous malformations, pyogenic granuloma, and hairy reconstructive flaps. Electronic medical records and photographic documentation were reviewed. Three blinded staff personnel not involved with patient care in this study evaluated photographs taken prior to the first and after the final laser treatments. Observers rated the percentage clearance of the lesions or the ablation of bleeding, and the assessed values were averaged for each patient.

RESULTS

An average of 30-95% lightening was observed in the intraoral port-wine stains, 90% in the hemangiomas, 70% in arteriovenous malformations, 81% for venous malformations, 86% for venous lakes, and 100% for the pyogenic granuloma. Bleeding was ablated in all hereditary hemorrhagic telangiectasia lesions treated using the pulsed dye laser with or without the Alexandrite laser. Intraoral hair growing on the skin paddle of microvascular flaps was completely removed in one of the three cases treated using the Alexandrite laser. In the two remaining cases, some hair removal was achieved, but because the residual hairs were grey or white (absence of melanocytic chromophore), photocoagulation was less effective.

CONCLUSION

Lasers are a safe and effective means to selectively destroy specific chromphores. Such specific targeting ensures complete destruction of pathological tissue, decreasing the possibility of relapse and/or recurrence. Selective laser treatment of benign intraoral lesions represents a niche application that fills a gap in the multidisciplinary management of several conditions such as oral vascular anomalies and hairy reconstructive flaps.

Genetic Variants Associated with Port-Wine Stains

Background

Port-wine stains (PWS) are capillary malformations, typically located in the dermis of the head and neck, affecting 0.3% of the population. Current theories suggest that port-wine stains are caused by somatic mutations that disrupt vascular development.

Objectives

Understanding PWS genetic determinants could provide insight into new treatments.

Methods

Our study used a custom next generation sequencing (NGS) panel and digital polymerase chain reaction to investigate genetic variants in 12 individuals with isolated port-wine stains. Importantly, affected and healthy skin tissue from the same individual were compared. A subtractive correction method was developed to eliminate background noise from NGS data. This allowed the detection of a very low level of mosaicism.

Results

A novel somatic variant GNAQ, c.547C>G, p.Arg183Gly was found in one case with 4% allele frequency. The previously reported GNAQ c.548G>A, p.Arg183Gln was confirmed in 9 of 12 cases with an allele frequency ranging from 1.73 to 7.42%. Digital polymerase chain reaction confirmed novel variants detected by next generation sequencing. Two novel somatic variants were also found in RASA1, although neither was predicted to be deleterious.

Conclusions

This is the second largest study on isolated, non-syndromic PWS. Our data suggest that GNAQ is the main genetic determinant in this condition. Moreover, isolated port-wine stains are distinct from capillary malformations seen in RASA1 disorders, which will be helpful in clinical evaluation.