Looking back and beyond the 2017 diagnostic criteria for hypermobile Ehlers-Danlos syndrome: A retrospective cross-sectional study from an Italian reference center.

The most common conditions with symptomatic joint hypermobility are hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorders (HSD). Diagnosing these overlapping connective tissue disorders remains challenging due to the lack of established causes and reliable diagnostic tests. hEDS is diagnosed applying the 2017 diagnostic criteria, and patients with symptomatic joint hypermobility but not fulfilling these criteria are labeled as HSD, which is not officially recognized by all healthcare systems. The 2017 criteria were introduced to improve diagnostic specificity but have faced criticism for being too stringent and failing to adequately capture the multisystemic involvement of hEDS. Herein, we retrospectively evaluated 327 patients from 213 families with a prior diagnosis of hypermobility type EDS or joint hypermobility syndrome based on Villefranche and Brighton criteria, to assess the effectiveness of the 2017 criteria in distinguishing between hEDS and HSD and document the frequencies of extra-articular manifestations. Based on our findings, we propose that the 2017 criteria should be made less stringent to include a greater number of patients who are currently encompassed within the HSD category. This will lead to improved diagnostic accuracy and enhanced patient care by properly capturing the diverse range of symptoms and manifestations present within the hEDS/HSD spectrum.

Despite celiprolol therapy, patients with vascular Ehlers-Danlos syndrome remain at risk of vascular events: A 12-year experience in an Italian referral center.

BACKGROUND: Vascular Ehlers-Danlos syndrome (vEDS) is an inherited connective tissue disorder characterized by arterial fragility. Celiprolol has been suggested to significantly reduce rates of vascular events in this setting, though real-world evidence is limited. The aim of this study was to report our experience with celiprolol therapy in vEDS management. METHODS: Patients with a genetically confirmed diagnosis of vEDS who were referred for outpatient consultation at the Brescia University Hospital between January 2011 and July 2023 were included. At each visit, patients' medical history, results of vascular imaging, and office blood pressure measurements were recorded. Celiprolol therapy was progressively titrated to the maximum tolerated dose of up to 400 mg daily, according to the patients' tolerance. RESULTS: Overall, 26 patients were included. Female sex was prevalent (62%). Mean (SD) age was 37 (16) years. Follow-up duration was 72 (41) months. At the last follow-up visit, all patients were on celiprolol therapy, 80% of whom were taking the maximum recommended dose. The yearly risk of symptomatic vascular events was 8.8%, the majority of which occurred after reaching the maximum recommended dose of celiprolol. No significant predictor of symptomatic vascular events was identified among patients' clinical characteristics. CONCLUSION: In our cohort, rates of celiprolol use were high and the drug was well tolerated overall. Nonetheless, the risk of symptomatic vascular events remained nonnegligible. Future studies should identify reliable predictors of major adverse events and explore additional therapeutic strategies that could further lower the risk of life-threatening events in this population.

Atypical variants in COL1A1 and COL3A1 associated with classical and vascular Ehlers-Danlos syndrome overlap phenotypes: expanding the clinical phenotype based on additional case reports.

The vast majority of reported (likely) pathogenic missense variants in the genes coding for the fibrillar collagens leads to the substitution of one of the obligatory glycine residues in the Gly-Xaa-Yaa repeat sequence of the triple helical domain. Their phenotypic consequences and deleterious effects have been well-documented. However, with increasing access to molecular diagnostic testing based on next-generation sequencing techniques, such as sequencing of multi-gene panels and whole-exome sequencing, non-glycine substitutions are more frequently identified in individuals suspected to have a heritable collagen disorder, but their pathogenic effect is often difficult to predict.Some specific non-glycine substitutions in the proα1(I)- (p.(Arg312Cys)) and proα1(III)- (glutamic acid to lysine at different positions) collagen chain have been identified in a number of individuals presenting a phenotype showing features of both classical and vascular Ehlers-Danlos syndrome. The number of reported individuals with these defects is currently very low, and several of these non-glycine substitutions had initially been categorised as variants of unknown significance (VUS), complicating early diagnosis, accurate counselling, management guidelines, and correct classification. This collaborative study reports on the phenotype of 22 and 7 individuals harbouring these rare variants in COL1A1 and COL3A1, respectively, expanding our knowledge on clinical presentation, phenotypic variability, and natural history, and informing on the risk for potentially life-threatening events, such as vascular, gastro-intestinal, and pregnancy-related complications.

Age-dependent effect of susceptibility factors on the risk of intracerebral haemorrhage: Multicenter Study on Cerebral Hemorrhage in Italy (MUCH-Italy).

OBJECTIVE: To investigate the age-dependent impact of traditional stroke risk factors on the occurrence of intracerebral haemorrhage (ICH). METHODS: We performed a case-control analysis, comparing consecutive patients with ICH with age-matched and sex-matched stroke-free controls, enrolled in the setting of the Multicenter Study on Cerebral Hemorrhage in Italy (MUCH-Italy) between 2002 and 2014 by multivariable logistic regression model within subgroups stratified by age quartiles (Q1-Q4). RESULTS: We analysed 3492 patients and 3492 controls. The impact of untreated hypertension on the risk of ICH was higher in the lower than in the upper age quartile (OR 11.64, 95% CI 7.68 to 17.63 in Q1 vs OR 6.05, 95% CI 3.09 to 11.85 in Q4 with intermediate ORs in Q2 and Q3), while the opposite trend was observed for untreated hypercholesterolaemia (OR 0.63, 95% CI 0.45 to 0.97 in Q1 vs OR 0.36, 95% CI 0.26 to 0.56 in Q4 with intermediate ORs in Q2 and Q3). The effect of untreated diabetes and excessive alcohol intake was detected only in the older age group (OR 3.63, 95% CI 1.22 to 10.73, and OR 1.69, 95% CI 1.13 to 2.51, respectively). CONCLUSIONS: Our findings provide evidence of age-dependent differences in the effects of susceptibility factors on the risk of ICH.

Clinical and Genetic Heterogeneity in a Large Family with Pseudoxanthoma Elasticum: MTHFR and SERPINE1 Variants as Possible Disease Modifiers in Developing Ischemic Stroke.

BACKGROUND AND OBJECTIVES: Pseudoxanthoma elasticum (PXE) is a rare autosomal recessive disorder caused by pathogenic variants in the ABCC6 gene. The phenotypic spectrum of PXE is highly variable and includes principally three major features: skin lesions, eye and vascular manifestations, while brain manifestations are less common. To date about 400 different PXE associated variants in ABCC6 gene are described without any evident genotype-phenotype correlation. Herein, we report the clinical and molecular findings of a large PXE family with clinical and genetic intra-familial variability with significant cerebrovascular involvement. METHODS: The analysis of the ABCC6 gene was performed in the proband and her familiars for the definition of genetic background. Then, in order to determine why some affected individuals had more prominent brain involvement, we investigated classic thrombophilic gene variants. RESULTS: Molecular findings disclosed two different ABCC6 mutations, i.e., the recurrent p.(Arg518Gln) and the novel p.(Val1285Met) missense substitution responsible of a pseudo-dominant inheritance. The study of thrombophilic gene variants revealed the presence of 4G/4G SERPINE1 genotype in the proband and in her father, which both developed ischemic stroke. The proband carried also the C677T variant the MTHFR gene. CONCLUSION: We argue, for the first time, that the 4G/4G SERPINE1 genotype could represent an additional risk factor in PXE for developing ischemic stroke, which adds up to the already known predisposing conditions. Therapeutic implications are discussed, we also advise that PXE patients should be adequately screened for cerebral vasculopathy, even more if familial history is suggestive of brain complications.

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.

COL1-related overlap disorder: A novel connective tissue disorder incorporating the osteogenesis imperfecta/Ehlers-Danlos syndrome overlap.

The 2017 classification of Ehlers-Danlos syndromes (EDS) identifies three types associated with causative variants in COL1A1/COL1A2 and distinct from osteogenesis imperfecta (OI). Previously, patients have been described with variable features of both disorders, and causative variants in COL1A1/COL1A2; but this phenotype has not been included in the current classification. Here, we expand and re-define this OI/EDS overlap as a missing EDS type. Twenty-one individuals from 13 families were reported, in whom COL1A1/COL1A2 variants were found after a suspicion of EDS. None of them could be classified as affected by OI or by any of the three recognized EDS variants associated with COL1A1/COL1A2. This phenotype is dominated by EDS-related features. OI-related features were limited to mildly reduced bone mass, occasional fractures and short stature. Eight COL1A1/COL1A2 variants were novel and five recurrent with a predominance of glycine substitutions affecting residues within the procollagen N-proteinase cleavage site of α1(I) and α2(I) procollagens. Selected variants were investigated by biochemical, ultrastructural and immunofluorescence studies. The pattern of observed changes in the dermis and in vitro for selected variants was more typical of EDS rather than OI. Our findings indicate the existence of a wider recognizable spectrum associated with COL1A1/COL1A2.

TAB2 c.1398dup variant leads to haploinsufficiency and impairs extracellular matrix homeostasis.

Transforming growth factor ß-activated kinase 1 (TAK1) mediates multiple biological processes through the nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and the mitogen-activated protein kinase (MAPK) signaling pathways. TAK1 activation is tightly regulated by its binding partners (TABs). In particular, binding with TAB2 is crucial for cardiovascular development and extracellular matrix (ECM) homeostasis. In our previous work, we reported a novel multisystem disorder associated with the heterozygous TAB2 c.1398dup variant. Here, we dissect the functional effects of this variant in order to understand its molecular pathogenesis. We demonstrate that TAB2 c.1398dup considerably undergoes to nonsense-mediated messenger RNA decay and encodes a truncated protein that loses its ability to bind TAK1. We also show an alteration of the TAK1 autophosphorylation status and of selected downstream signaling pathways in patients' fibroblasts. Immunofluorescence analyses and ECM-related polymerase chain reaction-array panels highlight that patient fibroblasts display ECM disorganization and altered expression of selected ECM components and collagen-related pathways. In conclusion, we deeply dissect the molecular pathogenesis of the TAB2 c.1398dup variant and show that the resulting phenotype is well explained by TAB2 loss-of-function. Our data also offer initial insights on the ECM homeostasis impairment as a molecular mechanism probably underlying a multisystem disorder linked to TAB2.

GARFIELD-NGS: Genomic vARiants FIltering by dEep Learning moDels in NGS.

Summary: Exome sequencing approach is extensively used in research and diagnostic laboratories to discover pathological variants and study genetic architecture of human diseases. However, a significant proportion of identified genetic variants are actually false positive calls, and this pose serious challenge for variants interpretation. Here, we propose a new tool named Genomic vARiants FIltering by dEep Learning moDels in NGS (GARFIELD-NGS), which rely on deep learning models to dissect false and true variants in exome sequencing experiments performed with Illumina or ION platforms. GARFIELD-NGS showed strong performances for both SNP and INDEL variants (AUC 0.71-0.98) and outperformed established hard filters. The method is robust also at low coverage down to 30X and can be applied on data generated with the recent Illumina two-colour chemistry. GARFIELD-NGS processes standard VCF file and produces a regular VCF output. Thus, it can be easily integrated in existing analysis pipeline, allowing application of different thresholds based on desired level of sensitivity and specificity. Availability and implementation: GARFIELD-NGS available at https://github.com/gedoardo83/GARFIELD-NGS. Supplementary information: Supplementary data are available at Bioinformatics online.

Dermal fibroblast-to-myofibroblast transition sustained by αvß3 integrin-ILK-Snail1/Slug signaling is a common feature for hypermobile Ehlers-Danlos syndrome and hypermobility spectrum disorders.

Hypermobile Ehlers-Danlos syndrome (hEDS) is a heritable connective tissue disorder with unknown molecular basis mainly characterized by generalized joint hypermobility, joint instability complications, and minor skin changes. The phenotypic spectrum is broad and includes multiple associated symptoms shared with chronic inflammatory systemic diseases. The stricter criteria defined in the 2017 EDS nosology leave without an identity many individuals with symptomatic joint hypermobility and/or features of hEDS; for these patients, the term Hypermobility Spectrum Disorders (HSD) was introduced. We previously reported that in vitro cultured hEDS and HSD patients' skin fibroblasts show a disarray of several extracellular matrix (ECM) components and dysregulated expression of genes involved in connective tissue homeostasis and inflammatory/pain/immune responses. Herein, we report that hEDS and HSD skin fibroblasts exhibit in vitro a similar myofibroblast-like phenotype characterized by the organization of α-smooth muscle actin cytoskeleton, expression of OB-cadherin/cadherin-11, enhanced migratory capability associated with augmented levels of the ECM-degrading metalloproteinase-9, and altered expression of the inflammation mediators CCN1/CYR61 and CCN2/CTGF. We demonstrate that in hEDS and HSD cells this fibroblast-to-myofibroblast transition is triggered by a signal transduction pathway that involves αvß3 integrin-ILK complexes, organized in focal adhesions, and the Snail1/Slug transcription factor, thus providing insights into the molecular mechanisms related to the pathophysiology of these protean disorders. The indistinguishable phenotype identified in hEDS and HSD cells resembles an inflammatory-like condition, which correlates well with the systemic phenotype of patients, and suggests that these multisystemic disorders might be part of a phenotypic continuum rather than representing distinct clinical entities.

COL6A5 variants in familial neuropathic chronic itch.

Itch is thought to represent the peculiar response to stimuli conveyed by somatosensory pathways shared with pain through the activation of specific neurons and receptors. It can occur in association with dermatological, systemic and neurological diseases, or be the side effect of certain drugs. However, some patients suffer from chronic idiopathic itch that is frequently ascribed to psychological distress and for which no biomarker is available to date. We investigated three multigenerational families, one of which diagnosed with joint hypermobility syndrome/Ehlers-Danlos syndrome hypermobility type (JHS/EDS-HT), characterized by idiopathic chronic itch with predominantly proximal distribution. Skin biopsy was performed in all eight affected members and revealed in six of them reduced intraepidermal nerve fibre density consistent with small fibre neuropathy. Whole exome sequencing identified two COL6A5 rare variants co-segregating with chronic itch in eight affected members and absent in non-affected members, and in one unrelated sporadic patient with type 1 painless diabetic neuropathy and chronic itch. Two families and the diabetic patient carried the nonsense c.6814G>T (p.Glu2272*) variant and another family carried the missense c.6486G>C (p.Arg2162Ser) variant. Both variants were predicted as likely pathogenic by in silico analyses. The two variants were rare (minor allele frequency < 0.1%) in 6271 healthy controls and absent in 77 small fibre neuropathy and 167 JHS/EDS-HT patients without itch. Null-allele test on cDNA from patients' fibroblasts of both families carrying the nonsense variant demonstrated functional haploinsufficiency due to activation of nonsense mediated RNA decay. Immunofluorescence microscopy and western blotting revealed marked disorganization and reduced COL6A5 synthesis, respectively. Indirect immunofluorescence showed reduced COL6A5 expression in the skin of patients carrying the nonsense variant. Treatment with gabapentinoids provided satisfactory itch relief in the patients carrying the mutations. Our findings first revealed an association between COL6A5 gene and familiar chronic itch, suggesting a new contributor to the pathogenesis of neuropathic itch and identifying a new candidate therapeutic target.

Multifaced Roles of the αvß3 Integrin in Ehlers-Danlos and Arterial Tortuosity Syndromes' Dermal Fibroblasts.

The αvß3 integrin, an endothelial cells' receptor-binding fibronectin (FN) in the extracellular matrix (ECM) of blood vessels, regulates ECM remodeling during migration, invasion, angiogenesis, wound healing and inflammation, and is also involved in the epithelial mesenchymal transition. In vitro-grown human control fibroblasts organize a fibrillar network of FN, which is preferentially bound on the entire cell surface to its canonical α5ß1 integrin receptor, whereas the αvß3 integrin is present only in rare patches in focal contacts. We report on the preferential recruitment of the αvß3 integrin, due to the lack of FN-ECM and its canonical integrin receptor, in dermal fibroblasts from Ehlers-Danlos syndromes (EDS) and arterial tortuosity syndrome (ATS), which are rare multisystem connective tissue disorders. We review our previous findings that unraveled different biological mechanisms elicited by the αvß3 integrin in fibroblasts derived from patients affected with classical (cEDS), vascular (vEDS), hypermobile EDS (hEDS), hypermobility spectrum disorders (HSD), and ATS. In cEDS and vEDS, respectively, due to defective type V and type III collagens, αvß3 rescues patients' fibroblasts from anoikis through a paxillin-p60Src-mediated cross-talk with the EGF receptor. In hEDS and HSD, without a defined molecular basis, the αvß3 integrin transduces to the ILK-Snail1-axis inducing a fibroblast-to-myofibroblast-transition. In ATS cells, the deficiency of the dehydroascorbic acid transporter GLUT10 leads to redox imbalance, ECM disarray together with the activation of a non-canonical αvß3 integrin-TGFBRII signaling, involving p125FAK/p60Src/p38MAPK. The characterization of these different biological functions triggered by αvß3 provides insights into the multifaced nature of this integrin, at least in cultured dermal fibroblasts, offering future perspectives for research in this field.

GLUT10 deficiency leads to oxidative stress and non-canonical αvß3 integrin-mediated TGFß 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 TGFß 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 TGFß signalling due to TGFBRI disorganization, the upregulation of TGFBRII and connective tissue growth factor, and the activation of the αvß3 integrin transduction pathway, which involves p125FAK, p60Src and p38 MAPK. Stable GLUT10 expression in patients' fibroblasts normalized redox homeostasis and PPARγ activity, rescued canonical TGFß 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.

Delineation of Ehlers-Danlos syndrome phenotype due to the c.934C>T, p.(Arg312Cys) mutation in COL1A1: Report on a three-generation family without cardiovascular events, and literature review.

Classical Ehlers-Danlos syndrome (cEDS) is a rare connective tissue disorder primarily characterized by hyperextensible skin, defective wound healing, abnormal scars, easy bruising, and generalized joint hypermobility; arterial dissections are rarely observed. Mutations in COL5A1 and COL5A2 encoding type V collagen account for more than 90% of the patients so far characterized. In addition, cEDS phenotype was reported in a small number of patients carrying the c.934C>T mutation in COL1A1 that results in an uncommon substitution of a non-glycine residue in one Gly-Xaa-Yaa repeat of the pro-α1(I)-chain p.(Arg312Cys), which leads to disturbed collagen fibrillogenesis due to delayed removal of the type I procollagen N-propeptide. This specific mutation has been associated with propensity to arterial rupture in early adulthood; indeed, in literature the individuals harboring this mutation are also referred to as "(classic) vascular-like" EDS patients. Herein, we describe a three-generation cEDS family with six adults carrying the p.(Arg312Cys) substitution, which show a variable and prevalent cutaneous involvement without any major vascular event. These data, together with those available in literature, suggest that vascular events are not a diagnostic handle to differentiate patients with the p.(Arg312Cys) COL1A1 mutation from those with COL5A1 and COL5A2 defects, and highlight that during the diagnostic process the presence of at least the p.(Arg312Cys) substitution in COL1A1 should be investigated in cEDS patients without type V collagen mutations. Nevertheless, for these patients, as well as for those affected with cEDS, a periodical vascular surveillance should be carried out together with cardiovascular risk factors monitoring. © 2016 Wiley Periodicals, Inc.

Marfan syndrome: Report of a complex phenotype due to a 15q21.1 contiguos gene deletion encompassing FBN1, and literature review.

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder that primarily involves skeletal, ocular, and cardiovascular systems with large inter- and intra-familial variability in terms of age of onset, severity, and aortic disease. The causal gene, FBN1, encodes for fibrillin 1, a multi-domain glycoprotein essential for many biological functions, including deposition and formation of elastic fibers. Reports describing chromosomal alterations involving FBN1 are rare, but in the last years their number has increased after copy number state analyses, such as multiplex ligation-dependent probe amplification and microarray-based comparative genomic hybridization, were adopted as routine diagnostic tools. Herein we report a patient with MFS and an atypical facial appearance and neuropsychiatric involvement likely not attributable to MFS due to a 15q21.1 deletion that involves part of FBN1 and 13 additional contiguous genes listed in OMIM. We compare his phenotype with those of the few patients described in the literature who share similar 15q11.2 deletions. This report expands the phenotype of patients with 15q11.2 deletion involving FBN1 and its contiguous genes, and suggests a possible role for these other genes in the pathogenesis of the observed unusual clinical signs that are not explained by FBN1 haploinsufficiency. © 2016 Wiley Periodicals, Inc.

Ehlers-Danlos syndrome with lethal cardiac valvular dystrophy in males carrying a novel splice mutation in FLNA.

Filamin A is an X-linked, ubiquitous actin-binding protein whose mutations are associated to multiple disorders with limited genotype-phenotype correlations. While gain-of-function mutations cause various bone dysplasias, loss-of-function variants are the most common cause of periventricular nodular heterotopias with variable soft connective tissue involvement, as well as X-linked cardiac valvular dystrophy (XCVD). The term "Ehlers-Danlos syndrome (EDS) with periventricular heterotopias" has been used in females with neurological, cardiovascular, integument and joint manifestations, but this nosology is still a matter of debate. We report the clinical and molecular update of an Italian family with an X-linked recessive soft connective tissue disorder and which was described, in 1975, as the first example of EDS type V of the Berlin nosology. The cutaneous phenotype of the index patient was close to classical EDS and all males died for a lethal cardiac valvular dystrophy. Whole exome sequencing identified the novel c.1829-1G>C splice variation in FLNA in two affected cousins. The nucleotide change was predicted to abolish the canonical splice acceptor site of exon 13 and to activate a cryptic acceptor site 15 bp downstream, leading to in frame deletion of five amino acid residues (p.Phe611_Gly615del). The predicted in frame deletion clusters with all the mutations previously identified in XCVD and falls within the N-terminus rod 1 domain of filamin A. Our findings expand the male-specific phenotype of FLNA mutations that now includes classical-like EDS with lethal cardiac valvular dystrophy, and offer further insights for the genotype-phenotype correlations within this spectrum. © 2016 Wiley Periodicals, Inc.

Arterial tortuosity in patients with spontaneous cervical artery dissection.

PURPOSE: The aim of this study was to test the hypothesis that patients with spontaneous cervical artery dissection (CeAD) have increased arterial tortuosity, and the objective quantification of such a tortuosity may aid in the identification of subjects at increased risk of disease. METHODS: In the setting of a hospital-based, case-control study, we used the vertebral tortuosity index (VTI) measured on magnetic resonance angiography, a validated method for the assessment and quantification of arterial tortuosity, to compare the degree of tortuosity in a series of consecutive patients with spontaneous CeAD and of age- and sex-matched patients with ischemic stroke unrelated to CeAD (non-CeAD IS) and stroke-free subjects. RESULTS: The study group was composed of 102 patients with CeAD (mean age, 44.5 ± 7.8 years; 66.7% men), 102 with non-CEAD IS, and 102 stroke-free subjects. The VTI was higher in the group of patients with CeAD (median, 7.3; 25th-75th percentile, 10.2) compared with that of non-CeAD IS (median, 3.4; 25th-75th percentile, 4.4) and of stroke-free subjects (median, 4.0; 25th-75th percentile, 2.9; p ≤ 0.001), and was independently associated to the risk of CeAD (OR, 1.18; 95% CI, 1.09-1.29) in multivariable regression analysis. The degree of tortuosity also tended to be higher in CeAD patients who experienced short-term recurrence (5.8%; median, 20.2; 25th-75th percentile, 31.2) than in those without recurrent events (median, 7.2; 25th-75th percentile, 9.4; p = 0.074). CONCLUSION: CeAD patients exhibit increased arterial tortuosity. This might have potential implications for better understanding of the pathophysiology of the disease as well as clinical utility in evaluation, prognostication, and decision-making of affected individuals.

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.