Intraperitoneal bladder rupture in a young child with vascular Ehlers-Danlos syndrome.

In this report, we present the case of a 3-year-old child with vascular Ehlers-Danlos syndrome (vEDS) previously known as Ehlers-Danlos syndrome type IV. After experiencing a minor traumatic injury to the abdomen, consisting of falling over a bathroom stool on the way to the restroom with a full bladder, the child developed acute abdominal pain. He was found to have an intraperitoneal bladder rupture that was successfully repaired with management techniques tailored to his known diagnosis of vEDS. While tissue fragility and internal organ rupture occurring with minor trauma are known complications of vEDS, this is the first case in the literature of a bladder rupture in a child with vEDS with a confirmed variant in the COL3A1 gene, to our knowledge. This case broadens the clinical presentation of vEDS, demonstrates that children can have life-threatening organ rupture at a young age, and may alert providers to consider this diagnosis when a child presents with bladder rupture.

Growth, development, and phenotypic spectrum of individuals with deletions of 2q33.1 involving SATB2.

SATB2-Associated syndrome (SAS) is an autosomal dominant, multisystemic, neurodevelopmental disorder due to alterations in SATB2 at 2q33.1. A limited number of individuals with 2q33.1 contiguous deletions encompassing SATB2 (ΔSAS) have been described in the literature. We describe 17 additional individuals with ΔSAS, review the phenotype of 33 previously published individuals with 2q33.1 deletions (n = 50, mean age = 8.5 ± 7.8 years), and provide a comprehensive comparison to individuals with other molecular mechanisms that result in SAS (non-ΔSAS). Individuals in the ΔSAS group were often underweight for age (20/41 = 49%) with a progressive decline in weight (95% CI = -2.3 to -1.1, p < 0.0001) and height (95% CI = -2.3 to -1.0, p < 0.0001) Z-score means from birth to last available measurement. ΔSAS individuals were often noted to have a broad spectrum of facial dysmorphism. A composite image of ΔSAS individuals generated by automated image analysis was distinct as compared to matched controls and non-ΔSAS individuals. We also present additional genotype-phenotype correlations for individuals in the ΔSAS group such as an increased risk for aortic root/ascending aorta dilation and primary pulmonary hypertension for those individuals with contiguous gene deletions that include COL3A1/COL5A2 and BMPR2, respectively. Based on these findings, we provide additional care recommendations for individuals with ΔSAS variants.

Type III collagen affects dermal and vascular collagen fibrillogenesis and tissue integrity in a mutant Col3a1 transgenic mouse model.

Type III collagen is a major fibrillar collagen consisting of three identical α1(III)-chains that is particularly present in tissues exhibiting elastic properties, such as the skin and the arterial wall. Heterozygous mutations in the COL3A1 gene result in vascular Ehlers-Danlos syndrome (vEDS), a severe, life-threatening disorder, characterized by thin, translucent skin and propensity to arterial, intestinal and uterine rupture. Most human vEDS cases result from a missense mutation substituting a crucial glycine residue in the triple helical domain of the α1(III)-chains. The mechanisms by which these mutant type III collagen molecules cause dermal and vascular fragility are not well understood. We generated a transgenic mouse line expressing mutant type III collagen, containing a typical helical glycine substitution (p.(Gly182Ser)). This Col3a1Tg-G182S mouse line displays a phenotype recapitulating characteristics of human vEDS patients with signs of dermal and vascular fragility. The Col3a1Tg-G182S mice develop severe transdermal skin wounds, resulting in early demise at 13-14weeks of age. We found that this phenotype was associated with a reduced total collagen content and an abnormal collagen III:I ratio, leading to the production of severely malformed collagen fibrils in the extracellular matrix of dermal and arterial tissues. These results indicate that expression of the glycine substitution in the α1(III)-chain disturbs formation of heterotypic type III:I collagen fibrils, and thereby demonstrate a key role for type III collagen in collagen fibrillogenesis in dermal and arterial tissues.

Angiotensin II promotes thoracic aortic dissections and ruptures in Col3a1 haploinsufficient mice.

Vascular Ehlers-Danlos syndrome is a dramatic inherited disease caused by mutations of type III collagen (COL3A1) gene, associated with early-onset occurrence of arterial ruptures. Col3a1(+/-) heterozygous mice, the only vascular Ehlers-Danlos syndrome model available to date, have no spontaneous early vascular phenotype. Our objective was to determine the susceptibility of Col3a1(+/-) mice to develop arterial ruptures under high blood pressure (BP) conditions induced by a 4-week infusion of angiotensin II (AngII). AngII (1 µg/kg per minute) significantly and comparably increased systolic BP in Col3a1(+/-) and Col3a1(+/+) mice but led to a higher premature mortality rate in Col3a1(+/-) mice compared with Col3a1(+/+) mice (73% versus 36%; P=0.03), particularly during the first-week infusion (55% versus 0%). Echocardiography and histological analysis evidenced that early deaths were caused by thoracic aortic ruptures preceded by dissections and associated with low aortic collagen fibrils content. Remarkably, lowering the dose of AngII (0.5 µg/kg per minute) rescued the first-week premature deaths of Col3a1(+/-) mice while decreasing the rises in systolic BP (P=0.05 compared with the high-dose AngII), resulting in similar mortality rates in both groups of mice at the end of the 4-week period (30% versus 50% in Col3a1(+/-) and Col3a1(+/+) mice; P=0.30). Finally, norepinephrine infusion (3.9 µg/kg per minute) did not induced significant mortality in both groups, whereas it significantly increased systolic BP, comparably with the high and with the low dose of AngII in Col3a1(+/-) mice (P=0.53 and P=1.00, respectively). Our findings demonstrated the extreme sensitivity of Col3a1 insufficient mice to prematurely develop thoracic aortic ruptures in response to AngII and its associated high levels in BP.

Loss of Col3a1, the gene for Ehlers-Danlos syndrome type IV, results in neocortical dyslamination.

It has recently been discovered that Collagen III, the encoded protein of the type IV Ehlers-Danlos Syndrome (EDS) gene, is one of the major constituents of the pial basement membrane (BM) and serves as the ligand for GPR56. Mutations in GPR56 cause a severe human brain malformation called bilateral frontoparietal polymicrogyria, in which neurons transmigrate through the BM causing severe mental retardation and frequent seizures. To further characterize the brain phenotype of Col3a1 knockout mice, we performed a detailed histological analysis. We observed a cobblestone-like cortical malformation, with BM breakdown and marginal zone heterotopias in Col3a1⁻/⁻ mouse brains. Surprisingly, the pial BM appeared intact at early stages of development but starting as early as embryonic day (E) 11.5, prominent BM defects were observed and accompanied by neuronal overmigration. Although collagen III is expressed in meningeal fibroblasts (MFs), Col3a1⁻/⁻ MFs present no obvious defects. Furthermore, the expression and posttranslational modification of α-dystroglycan was undisturbed in Col3a1⁻/⁻ mice. Based on the previous finding that mutations in COL3A1 cause type IV EDS, our study indicates a possible common pathological pathway linking connective tissue diseases and brain malformations.

Periodontal Ehlers-Danlos syndrome associated with type III and I collagen deficiencies.

In 1997, Ehlers-Danlos syndrome type VIII (EDS-VIII) was excluded from the diagnostic categories as there were insufficient data regarding the clinical features and the precise underlying molecular basis. However, a recent review of published cases shows that EDS-VIII has distinctive clinical features, which would suggest that it should be considered as a separate entity in future nosological classifications. The underlying molecular defect in EDS-VIII is unknown. A reduction of collagen type III was reported in a single case, but no consistent biochemical or structural changes are detectable. We report a patient with EDS-VIII who showed a reduction in the collagen type I and type III synthesis rates. Type I and type III procollagen and collagen synthesis and secretion rates were investigated in cultured fibroblasts and compared with five healthy controls and three patients with EDS type IV whose fibroblasts were cultured in parallel.

Chronic venous insufficiency: dysregulation of collagen synthesis.

Varicose vein disease is a common condition. Its pathology is not well characterized. A disorganization of smooth muscle cells and extracellular matrix components in the venous wall have been described. The objective of this paper is to offer an explanation for the abnormal distensibility of varicose veins. The content of hydroxyproline was quantified in control and varicose human saphenous veins. The synthesis of collagen types I, III, and V was quantified in cultured venous smooth muscle cells and dermal fibroblasts of control subjects and patients with varicose veins. The proportion of collagen type III in the heterofibrils composed by collagen types I, III, and V was calculated. The level of hydroxyproline was increased in varicose veins, suggesting an increased content of collagen. This augmentation of collagen in diseased tissues appears to be correlated with an increase of collagen type I since the collagen I mRNA was overexpressed in varicose veins, whereas collagen type III mRNA was not altered. The quantification of collagen synthesis in cultured cells shows that proportion of collagen type III was significantly decreased in cultured smooth muscle cells and dermal fibroblasts derived from patients with varicose veins. The results indicate a deficiency in collagen type III in patients with varicose veins. Since collagen type III is involved in tissue elasticity, these results offer an explanation for the abnormal distensibility of varicose veins. Moreover, this defect seems to be generalized in different tissues and argues in favor of a genetic alteration of remodeling in these patients.