Adult presentation of arterial tortuosity syndrome in a 51-year-old woman with a novel homozygous c.1411+1G>A mutation in the SLC2A10 gene

Metabolic Cardiomyopathies and Cardiac Defects in Inherited Disorders of Carbohydrate Metabolism: A Systematic Review

Heart failure (HF) is a progressive chronic disease that remains a primary cause of death worldwide, affecting over 64 million patients. HF can be caused by cardiomyopathies and congenital cardiac defects with monogenic etiology. The number of genes and monogenic disorders linked to development of cardiac defects is constantly growing and includes inherited metabolic disorders (IMDs). Several IMDs affecting various metabolic pathways have been reported presenting cardiomyopathies and cardiac defects. Considering the pivotal role of sugar metabolism in cardiac tissue, including energy production, nucleic acid synthesis and glycosylation, it is not surprising that an increasing number of IMDs linked to carbohydrate metabolism are described with cardiac manifestations. In this systematic review, we offer a comprehensive overview of IMDs linked to carbohydrate metabolism presenting that present with cardiomyopathies, arrhythmogenic disorders and/or structural cardiac defects. We identified 58 IMDs presenting with cardiac complications: 3 defects of sugar/sugar-linked transporters (GLUT3, GLUT10, THTR1); 2 disorders of the pentose phosphate pathway (G6PDH, TALDO); 9 diseases of glycogen metabolism (GAA, GBE1, GDE, GYG1, GYS1, LAMP2, RBCK1, PRKAG2, G6PT1); 29 congenital disorders of glycosylation (ALG3, ALG6, ALG9, ALG12, ATP6V1A, ATP6V1E1, B3GALTL, B3GAT3, COG1, COG7, DOLK, DPM3, FKRP, FKTN, GMPPB, MPDU1, NPL, PGM1, PIGA, PIGL, PIGN, PIGO, PIGT, PIGV, PMM2, POMT1, POMT2, SRD5A3, XYLT2); 15 carbohydrate-linked lysosomal storage diseases (CTSA, GBA1, GLA, GLB1, HEXB, IDUA, IDS, SGSH, NAGLU, HGSNAT, GNS, GALNS, ARSB, GUSB, ARSK). With this systematic review we aim to raise awareness about the cardiac presentations in carbohydrate-linked IMDs and draw attention to carbohydrate-linked pathogenic mechanisms that may underlie cardiac complications.

Arterial Tortuosity Syndrome in a Newborn: A Case Report With Literature Review

Arterial tortuosity syndrome (ATS; OMIM #208050) is a sporadic, autosomal, recessively inherited genetic disorder. ATS primarily causes the tortuosity and elongation of large and medium-sized arteries; however, other skeletal manifestations include dysmorphic features, such as hyperextensible skin, hypermobile joints, and congenital contractures. The present article reports the case of a female neonate, who, at birth, exhibited abnormal facial features, hypermobility of joints, and abnormal physical appearance. The patient was diagnosed with ATS during the first week of life, based on computed tomographic scans. In addition, angiographic results demonstrated elongation and tortuosity of the aorta, which were further supported using the results of genetic analysis. Mutation analysis of the solute carrier family 2 member 10 (SLC2A10) genes (Entrez Gene: 81031) detected a homozygous pathogenic c.243C>G (p. Ser81Arg) variant (dbSNP: rs80358230) in this patient, which supports the clinical diagnosis of ATS. Following the initial diagnosis, further investigations into the family history were carried out, and the results demonstrated that the patient's paternal grandmother and paternal aunt were also positive for ATS. The patient was subsequently referred to a tertiary care center for genetic counseling and further follow-up. Notably, carrier testing for at-risk relatives is recommended to identify family members that may be affected by this condition.

Two fetuses in one family of arterial tortuosity syndrome: prenatal ultrasound diagnosis

Background

Arterial tortuosity syndrome (ATS) is a rare autosomal recessive connective tissue disorder chiefly characterized by elongated and tortuosity of the large and medium sized arteries and anomalies of the vascular elastic fibers. Here we reported cases of brother about ATS from the same family on the prenatal ultrasound diagnosis. Reports of this case are rare in antenatally and we draw the vessel simulated diagram to display visually.

Case presentation

Prenatal ultrasound scanning at 29 weeks of gestation of the first fetus showed obvious tortuous and elongated of the aortic arch, ductus arteriosus, left and right pulmonary arteries, carotid and subclavian arteries. Three months after delivery, Contrast-enhanced computed tomography images (CTA) were performed to clearly display vascular abnormalities consistent with prenatal diagnosis of ultrasound. Whole exome sequencing (WES) was performed eight months after birth, two heterozygous variants of SLC2A10 gene was detected in newborn and their father and mother, respectively. Prenatal ultrasound scan at 22 weeks of gestation of the second fetus showed similar cardiovascular imaging. After birth the siblings have facial characteristic features gradually as aging. No surgical intervention was performed in the siblings follow up 19 months.

Conclusions

The key points of prenatal ultrasound diagnosis of ATS are the elongation and tortuosity of the large and medium sized arteries. Genetic counseling is the process of providing individuals and families with information on the nature, inheritance, and implications of genetic disorders to help them make informed medical and personal decisions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03960-w.

Slc2a10 knock-out mice deficient in ascorbic acid synthesis recapitulate aspects of arterial tortuosity syndrome and display mitochondrial respiration defects

Arterial tortuosity syndrome (ATS) is a recessively inherited connective tissue disorder, mainly characterized by tortuosity and aneurysm formation of the major arteries. ATS is caused by loss-of-function mutations in SLC2A10, encoding the facilitative glucose transporter GLUT10. Former studies implicated GLUT10 in the transport of dehydroascorbic acid, the oxidized form of ascorbic acid (AA). Mouse models carrying homozygous Slc2a10 missense mutations did not recapitulate the human phenotype. Since mice, in contrast to humans, are able to intracellularly synthesize AA, we generated a novel ATS mouse model, deficient for Slc2a10 as well as Gulo, which encodes for L-gulonolactone oxidase, an enzyme catalyzing the final step in AA biosynthesis in mouse. Gulo;Slc2a10 double knock-out mice showed mild phenotypic anomalies, which were absent in single knock-out controls. While Gulo;Slc2a10 double knock-out mice did not fully phenocopy human ATS, histological and immunocytochemical analysis revealed compromised extracellular matrix formation. Transforming growth factor beta signaling remained unaltered, while mitochondrial function was compromised in smooth muscle cells derived from Gulo;Slc2a10 double knock-out mice. Altogether, our data add evidence that ATS is an ascorbate compartmentalization disorder, but additional factors underlying the observed phenotype in humans remain to be determined.

Arterial Tortuosity Syndrome: An Ascorbate Compartmentalization Disorder?

Significance: Cardiovascular disorders are the most important cause of morbidity and mortality in the Western world. Monogenic developmental disorders of the heart and vessels are highly valuable to study the physiological and pathological processes in cardiovascular system homeostasis. The arterial tortuosity syndrome (ATS) is a rare, autosomal recessive connective tissue disorder showing lengthening, tortuosity, and stenosis of the large arteries, with a propensity for aneurysm formation. In histopathology, it associates with fragmentation and disorganization of elastic fibers in several tissues, including the arterial wall. ATS is caused by pathogenic variants in SLC2A10 encoding the facilitative glucose transporter (GLUT)10. Critical Issues: Although several hypotheses have been forwarded, the molecular mechanisms linking disrupted GLUT10 activity with arterial malformations are largely unknown. Recent Advances: The vascular and systemic manifestations and natural history of ATS patients have been largely delineated. GLUT10 was identified as an intracellular transporter of dehydroascorbic acid, which contributes to collagen and elastin cross-linking in the endoplasmic reticulum, redox homeostasis in the mitochondria, and global and gene-specific methylation/hydroxymethylation affecting epigenetic regulation in the nucleus. We revise here the current knowledge on ATS and the role of GLUT10 within the compartmentalization of ascorbate in physiological and diseased states. Future Directions: Centralization of clinical, treatment, and outcome data will enable better management for ATS patients. Establishment of representative animal disease models could facilitate the study of pathomechanisms underlying ATS. This might be relevant for other forms of vascular dysplasia, such as isolated aneurysm formation, hypertensive vasculopathy, and neovascularization. Antioxid. Redox Signal. 34, 875-889.

Multisystemic manifestations in a cohort of 75 classical Ehlers-Danlos syndrome patients: natural history and nosological perspectives

Background

The Ehlers-Danlos syndromes (EDS) are rare connective tissue disorders consisting of 13 subtypes with overlapping features including joint hypermobility, skin and generalized connective tissue fragility. Classical EDS (cEDS) is principally caused by heterozygous COL5A1 or COL5A2 variants and rarely by the COL1A1 p.(Arg312Cys) substitution. Current major criteria are (1) skin hyperextensibility plus atrophic scars and (2) generalized joint hypermobility (gJHM). Minor criteria include additional mucocutaneous signs, epicanthal folds, gJHM complications, and an affected first-degree relative. Minimal criteria prompting molecular testing are major criterion 1 plus either major criterion 2 or 3 minor criteria. In addition to these features, the clinical picture also involves multiple organ systems, but large-scale cohort studies are still missing. This study aimed to investigate the multisystemic involvement and natural history of cEDS through a cross-sectional study on a cohort of 75 molecularly confirmed patients evaluated from 2010 to 2019 in a tertiary referral center. The diagnostic criteria, additional mucocutaneous, osteoarticular, musculoskeletal, cardiovascular, gastrointestinal, uro-gynecological, neuropsychiatric, and atopic issues, and facial/ocular features were ascertained, and feature rates compared by sex and age.

Results

Our study confirms that cEDS is mainly characterized by cutaneous and articular involvement, though none of their hallmarks was represented in all cases and suggests a milder multisystemic involvement and a more favorable natural history compared to other EDS subtypes. Abnormal scarring was the most frequent and characteristic sign, skin hyperextensibility and gJHM were less common, all without any sex and age bias; joint instability complications were more recurrent in adults. Some orthopedic features showed a high prevalence, whereas the other issues related to the investigated organ systems were less recurrent with few exceptions and age-related differences.

Conclusions

Our findings define the diagnostic relevance of cutaneous and articular features and additional clinical signs associated to cEDS. Furthermore, our data suggest an update of the current EDS nosology concerning scarring that should be considered separately from skin hyperextensibility and that the clinical diagnosis of cEDS may be enhanced by the accurate evaluation of orthopedic manifestations at all ages, faciocutaneous indicators in children, and some acquired traits related to joint instability complications, premature skin aging, and patterning of abnormal scarring in older individuals.

Glucose Transport and Transporters in the Endomembranes

Glucose is a basic nutrient in most of the creatures; its transport through biological membranes is an absolute requirement of life. This role is fulfilled by glucose transporters, mediating the transport of glucose by facilitated diffusion or by secondary active transport. GLUT (glucose transporter) or SLC2A (Solute carrier 2A) families represent the main glucose transporters in mammalian cells, originally described as plasma membrane transporters. Glucose transport through intracellular membranes has not been elucidated yet; however, glucose is formed in the lumen of various organelles. The glucose-6-phosphatase system catalyzing the last common step of gluconeogenesis and glycogenolysis generates glucose within the lumen of the endoplasmic reticulum. Posttranslational processing of the oligosaccharide moiety of glycoproteins also results in intraluminal glucose formation in the endoplasmic reticulum (ER) and Golgi. Autophagic degradation of polysaccharides, glycoproteins, and glycolipids leads to glucose accumulation in lysosomes. Despite the obvious necessity, the mechanism of glucose transport and the molecular nature of mediating proteins in the endomembranes have been hardly elucidated for the last few years. However, recent studies revealed the intracellular localization and functional features of some glucose transporters; the aim of the present paper was to summarize the collected knowledge.

Application of the 2017 criteria for vascular Ehlers-Danlos syndrome in 50 patients ascertained according to the Villefranche nosology

Vascular Ehlers-Danlos syndrome (vEDS) is a rare inherited connective tissue disorder due to heterozygous pathogenic COL3A1 variants. Arterial, intestinal, and/or uterine fragility is the disease hallmark and results in reduced life expectancy. The clinical diagnosis is not always straightforward and patients' selection for molecular confirmation depends on the characteristics of applied criteria, that is, the Villefranche criteria (in use until 2017) and their revision according to the new EDS nosology. Herein, we reassessed the clinical features of 50 molecularly proven vEDS patients, diagnosed according to the Villefranche nosology between 2000 and 2016, using the 2017 classification in order to explore its clinical application. Our findings indicate that the Villefranche criteria were particularly valuable for symptomatic patients, even if with a limited specificity. Our study also suggests that the revised vEDS criteria, although expected to be more specific, might have a poorer accuracy, principally in terms of sensitivity. Both sets of criteria are less effective in presymptomatic young patients, especially in the absence of a clear-cut family history. For these patients, the careful evaluation of the cutaneous, articular, and dysmorphic features and, above all, genetic testing remain crucial to set-up proper follow-up and surveillance before catastrophic vascular and intestinal events.

Decreased Nuclear Ascorbate Accumulation Accompanied with Altered Genomic Methylation Pattern in Fibroblasts from Arterial Tortuosity Syndrome Patients

Ascorbate requiring Fe²⁺/2-oxoglutarate-dependent dioxygenases located in the nucleoplasm have been shown to participate in epigenetic regulation of gene expression via histone and DNA demethylation. Transport of dehydroascorbic acid is impaired in the endomembranes of fibroblasts from arterial tortuosity syndrome (ATS) patients, due to the mutation in the gene coding for glucose transporter GLUT10. We hypothesized that altered nuclear ascorbate concentration might be present in ATS fibroblasts, affecting dioxygenase activity and DNA demethylation. Therefore, our aim was to characterize the subcellular distribution of vitamin C, the global and site-specific changes in 5-methylcytosine and 5-hydroxymethylcytosine levels, and the effect of ascorbate supplementation in control and ATS fibroblast cultures. Diminished nuclear accumulation of ascorbate was found in ATS fibroblasts upon ascorbate or dehydroascorbic acid addition. Analyzing DNA samples of cultured fibroblasts from controls and ATS patients, a lower global 5-hydroxymethylcytosine level was found in ATS fibroblasts, which could not be significantly modified by ascorbate addition. Investigation of the (hydroxy)methylation status of specific regions in six candidate genes related to ascorbate metabolism and function showed that ascorbate addition could stimulate hydroxymethylation and active DNA demethylation at the PPAR-γ gene region in control fibroblasts only. The altered DNA hydroxymethylation patterns in patient cells both at the global level and at specific gene regions accompanied with decreased nuclear accumulation of ascorbate suggests the epigenetic role of vitamin C in the pathomechanism of ATS. The present findings represent the first example for the role of vitamin C transport in epigenetic regulation suggesting that ATS is a compartmentalization disease.

Genetic testing for Marfan-like disorders

Marfan-like disorders are inherited conditions with features resembling Marfan syndrome but without a pathogenic variant in FBN1, and/or without a clinical diagnosis of Marfan syndrome according to the Revised Ghent criteria, and/or with a pathogenic variant in a different disease gene. Marfan-like disorders are clinically and genetically heterogeneous and have variable prognosis. They may have autosomal dominant or autosomal recessive patterns of inheritance. The prevalence of most Mar-fan-like disorders is unknown. This Utility Gene Test was prepared on the basis of an analysis of the literature and existing diagnostic protocols. Molecular testing is useful for diagnosis confirmation, as well as differential diagnosis, appropriate genetic counselling and access to clinical trials.

GLUT10-Lacking in Arterial Tortuosity Syndrome-Is Localized to the Endoplasmic Reticulum of Human Fibroblasts

GLUT10 belongs to a family of transporters that catalyze the uptake of sugars/polyols by facilitated diffusion. Loss-of-function mutations in the SLC2A10 gene encoding GLUT10 are responsible for arterial tortuosity syndrome (ATS). Since subcellular distribution of the transporter is dubious, we aimed to clarify the localization of GLUT10. In silico GLUT10 localization prediction suggested its presence in the endoplasmic reticulum (ER). Immunoblotting showed the presence of GLUT10 protein in the microsomal, but not in mitochondrial fractions of human fibroblasts and liver tissue. An even cytosolic distribution with an intense perinuclear decoration of GLUT10 was demonstrated by immunofluorescence in human fibroblasts, whilst mitochondrial markers revealed a fully different decoration pattern. GLUT10 decoration was fully absent in fibroblasts from three ATS patients. Expression of exogenous, tagged GLUT10 in fibroblasts from an ATS patient revealed a strict co-localization with the ER marker protein disulfide isomerase (PDI). The results demonstrate that GLUT10 is present in the ER.

Things may not go as planned: The role of aortoiliac dilation and elongation during the estimation vascular structures' anatomical course

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Variation of aortic morphology such as aortic dimensions, branching points, and correlation with adjacent structures is highlighted.

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The mechanism of variance relies on the diseases such as arteriosclerosis, syphilis and hypertension.

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Patients with hypertension, atherosclerosis, and aortic aneurysm should be excluded from the study because of the variation of aortic morphology is concluded.

Glucose transporter type 10-lacking in arterial tortuosity syndrome-facilitates dehydroascorbic acid transport

Loss-of-function mutations in the gene encoding GLUT10 are responsible for arterial tortuosity syndrome (ATS), a rare connective tissue disorder. In this study GLUT10-mediated dehydroascorbic acid (DAA) transport was investigated, supposing its involvement in the pathomechanism. GLUT10 protein produced by in vitro translation and incorporated into liposomes efficiently transported DAA. Silencing of GLUT10 decreased DAA transport in immortalized human fibroblasts whose plasma membrane was selectively permeabilized. Similarly, the transport of DAA through endomembranes was markedly reduced in fibroblasts from ATS patients. Re-expression of GLUT10 in patients' fibroblasts restored DAA transport activity. The present results demonstrate that GLUT10 is a DAA transporter and DAA transport is diminished in the endomembranes of fibroblasts from ATS patients.

A combined vascular surgical and clinical genetics approach to diffuse aneurysmal disease

We report two patients who presented with extensive aneurysmal disease, in association with minimal external physical signs. Patient 1 remained genetically undiagnosed despite multiple structural, biochemical and genetic investigations. He made a good recovery following surgery for popliteal and left axillary artery aneurysms. Patient 2 was diagnosed with vascular type Ehlers-Danlos syndrome, associated with a high degree of tissue and blood vessel fragility, and is being managed conservatively. Early multidisciplinary assessment of such patients facilitates accurate diagnosis and management.

GLUT10 deficiency leads to oxidative stress and non-canonical αvβ3 integrin-mediated TGFβ signalling associated with extracellular matrix disarray in arterial tortuosity syndrome skin fibroblasts

Arterial tortuosity syndrome (ATS) is an autosomal recessive connective tissue disorder caused by loss-of-function mutations in SLC2A10, which encodes facilitative glucose transporter 10 (GLUT10). The role of GLUT10 in ATS pathogenesis remains an enigma, and the transported metabolite(s), i.e. glucose and/or dehydroascorbic acid, have not been clearly elucidated. To discern the molecular mechanisms underlying the ATS aetiology, we performed gene expression profiling and biochemical studies on skin fibroblasts. Transcriptome analyses revealed the dysregulation of several genes involved in TGFβ signalling and extracellular matrix (ECM) homeostasis as well as the perturbation of specific pathways that control both the cell energy balance and the oxidative stress response. Biochemical and functional studies showed a marked increase in ROS-induced lipid peroxidation sustained by altered PPARγ function, which contributes to the redox imbalance and the compensatory antioxidant activity of ALDH1A1. ATS fibroblasts also showed activation of a non-canonical TGFβ signalling due to TGFBRI disorganization, the upregulation of TGFBRII and connective tissue growth factor, and the activation of the αvβ3 integrin transduction pathway, which involves p125FAK, p60Src and p38 MAPK. Stable GLUT10 expression in patients' fibroblasts normalized redox homeostasis and PPARγ activity, rescued canonical TGFβ signalling and induced partial ECM re-organization. These data add new insights into the ATS dysregulated biological pathways and definition of the pathomechanisms involved in this disorder.

Arterial Tortuosity Syndrome: homozygosity for two novel and one recurrent SLC2A10 missense mutations in three families with severe cardiopulmonary complications in infancy and a literature review

Background

Arterial Tortuosity Syndrome (ATS) is a very rare autosomal recessive connective tissue disorder (CTD) characterized by tortuosity and elongation of the large- and medium-sized arteries and a propensity for aneurysm formation and vascular dissection. During infancy, children frequently present the involvement of the pulmonary arteries (elongation, tortuosity, stenosis) with dyspnea and cyanosis. Other CTD signs of ATS are dysmorphisms, abdominal hernias, joint hypermobility, skeletal abnormalities, and keratoconus. ATS is typically described as a severe disease with high rate of mortality due to major cardiovascular malformations. ATS is caused by mutations in the SLC2A10 gene, which encodes the facilitative glucose transporter 10 (GLUT10). Approximately 100 ATS patients have been described, and 21 causal mutations have been identified in the SLC2A10 gene.

Case presentation

We describe the clinical findings and molecular characterization of three new ATS families, which provide insight into the clinical phenotype of the disorder; furthermore, we expand the allelic repertoire of SLC2A10 by identifying two novel mutations. We also review the ATS patients characterized by our group and compare their clinical findings with previous data.

Conclusions

Our data confirm that the cardiovascular prognosis in ATS is less severe than previously reported and that the first years of life are the most critical for possible life-threatening events. Molecular diagnosis is mandatory to distinguish ATS from other CTDs and to define targeted clinical follow-up and timely cardiovascular surgical or interventional treatment, when needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-014-0122-5) contains supplementary material, which is available to authorized users.