Background: Classic Ehlers–Danlos syndrome (cEDS) is a rare autosomal dominant connective tissue disorder that is primarily characterized by skin hyperextensibility, abnormal wound healing/atrophic scars, and joint hypermobility. A recent study demonstrated that more than 90% of patients who satisfy all of these major criteria harbor a type V collagen (COLLV) defect. Methods: This cohort included 40 patients with cEDS who were clinically diagnosed according to the Villefranche nosology. The flowchart that was adopted for mutation detection consisted of sequencing the COL5A1 gene and, if no mutation was detected, COL5A2 analysis. In the negative patients the presence of large genomic rearrangements in COL5A1 was investigated using MLPA, and positive results were confirmed via SNP-array analysis. Results: We report the clinical and molecular characterization of 40 patients from 28 families, consisting of 14 pediatric patients and 26 adults. A family history of cEDS was present in 9 patients. The majority of the patients fulfilled all the major diagnostic criteria for cEDS; atrophic scars were absent in 2 females, skin hyperextensibility was not detected in a male and joint hypermobility was negative in 8 patients (20% of the entire cohort). Wide inter- and intra-familial phenotypic heterogeneity was observed. We identified causal mutations with a detection rate of approximately 93%. In 25/28 probands, COL5A1 or COL5A2 mutations were detected. Twenty-one mutations were in the COL5A1 gene, 18 of which were novel (2 recurrent). Of these, 16 mutations led to nonsense-mediated mRNA decay (NMD) and to COLLV haploinsufficiency and 5 mutations were structural. Two novel COL5A2 splice mutations were detected in patients with the most severe phenotypes. The known p. (Arg312Cys) mutation in the COL1A1 gene was identified in one patient with vascular-like cEDS. Conclusions: Our findings highlight that the three major criteria for cEDS are useful and sufficient for cEDS clinical diagnosis in the large majority of the patients. The borderline patients for whom these criteria fail can be diagnosed when minor signs of connective tissue diseases and family history are present and when genetic testing reveals a defect in COLLV. Our data also confirm that COL5A1 and COL5A2 are the major, if not the only, genes involved in cEDS.

The Ehlers‒Danlos syndromes (EDS) constitute a heterogenous group of connective tissue disorders characterized by joint hypermobility, skin abnormalities, and vascular fragility. The latest nosology recognizes 13 types caused by pathogenic variants in genes encoding collagens and other molecules involved in collagen processing and extracellular matrix (ECM) biology. Classical (cEDS), vascular (vEDS), and hypermobile (hEDS) EDS are the most frequent types. cEDS and vEDS are caused respectively by defects in collagen V and collagen III, whereas the molecular basis of hEDS is unknown. For these disorders, the molecular pathology remains poorly studied. Herein, we review, expand, and compare our previous transcriptome and protein studies on dermal fibroblasts from cEDS, vEDS, and hEDS patients, offering insights and perspectives in their molecular mechanisms. These cells, though sharing a pathological ECM remodeling, show differences in the underlying pathomechanisms. In cEDS and vEDS fibroblasts, key processes such as collagen biosynthesis/processing, protein folding quality control, endoplasmic reticulum homeostasis, autophagy, and wound healing are perturbed. In hEDS cells, gene expression changes related to cell-matrix interactions, inflammatory/pain responses, and acquisition of an in vitro pro-inflammatory myofibroblast-like phenotype may contribute to the complex pathogenesis of the disorder. Finally, emerging findings from miRNA profiling of hEDS fibroblasts are discussed to add some novel biological aspects about hEDS etiopathogenesis.

Background and Purpose—: The effect of obesity on the risk of intracerebral hemorrhage (ICH) may depend on the pathophysiology of vessel damage. To further address this issue, we investigated and quantified the correlations between obesity and obesity-related conditions in the causal pathways leading to ICH. Methods—: A total of 777 ICH cases ≥55 years of age (287 lobar ICH and 490 deep ICH) were consecutively enrolled as part of the Multicenter Study on Cerebral Hemorrhage in Italy and compared with 2083 control subjects by a multivariate path analysis model. Separate analyses were conducted for deep and lobar ICH. Results—: Obesity was not independently associated with an increased risk of lobar ICH (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.58–1.01) or deep ICH (OR, 1.18; 95% CI, 0.95–1.45) when compared with control subjects. The path analysis confirmed the nonsignificant total effect of obesity on the risk of lobar ICH (OR, 0.77; 95% CI, 0.58–1.02) but demonstrated a significant indirect effect on the risk of deep ICH (OR, 1.28; 95% CI, 1.03–1.57), mostly determined by hypertension (OR, 1.07; 95% CI, 1.04–1.11) and diabetes mellitus (OR, 1.04; 95% CI, 1.01–1.07). Obesity was also associated with an increased risk of deep ICH when compared with lobar ICH (OR, 1.62; 95% CI, 1.14–2.31). Conclusions—: Obesity increases the risk of deep ICH, mostly through an indirect effect on hypertension and other intermediate obesity-related comorbidities, but has no major influence on the risk of lobar ICH. This supports the hypothesis of different, vessel-specific, biological mechanisms underlying the relationship between obesity and cerebral hemorrhage.