Marfan syndrome is an autosomal dominant systemic disorder of the connective tissue. Children affected by the Marfan syndrome carry a mutation in one of their two copies of the gene that encodes the connective tissue protein fibrillin-1. Marfan syndrome affects most organs and tissues, especially the skeleton, lungs, eyes, heart, and the large blood vessel that distributes blood from the heart to the rest of the body. A case report of Marfan syndrome has been reported with oral features. The dental problems of the child were treated under general anesthesia and a one-month review showed intact stainless steel crowns' restorations and no signs of secondary caries.

Marfan syndrome (MFS) is an inherited connective tissue disorder. As the spinal growth depends on delicate balance of forces, conditions that affect musculoskeletal matrix often lead to spinal deformities. A large cross-sectional study revealed a 63% prevalence of scoliosis among patients with MFS. Multi-ethnic genome-wide association studies and analyses of human genetic mutations showed that variations and mutations of G protein-coupled receptor 126 (GPR126)locus are associated with multiple skeletal defects, including shorter stature and adolescent idiopathic scoliosis. The study included 54 patients with MFS and 196 control patients. The DNA was extracted from peripheral blood using the saline expulsion method and single nucleotide polymorphism (SNP) determination was carried out using TaqMan probes. Allelic discrimination was performed by RT-qPCR. Significant differences in genotype frequencies were found for SNP rs6570507 in relation to MFS and sex (recessive model, OR 2.46, 95% CI 1.03 -5.87; P = 0.03) and rs7755109 (overdominant model, OR 0.39, 95% CI 0.16-0.91; P = 0.03). The most significant association was found in SNP rs7755109, where the frequency of genotype AG was significantly different between MFS patients with scoliosis and those without (OR 5.68, 95% CI 1.09-29.48; P=0.04). This study, for the first time, examined the genetic association of SNP GPR126 with the risk of scoliosis in patients with connective tissue diseases. The study revealed that SNP rs7755109 is associated with the presence of scoliosis in Mexican patients with MFS.

Between August 1983 and January 1991, seven patients with Marfan syndrome underwent surgery for severe cardiovascular complications. The mean age at presentation was 5.7 months (range 4 to 9 months) in the infant group (n = 3), and 13.3 years (range 10 to 16 years) in a group of older children (n = 4). The primary indications for surgery in the infant group (performed at a mean of 3 years after diagnosis) were ascending aortic aneurysm with valvar regurgitation in one patient, and severe mitral valve prolapse with regurgitation in two. In the older group, surgical indications (performed at a mean of 2.8 years after diagnosis) were ascending aortic aneurysm with valvar regurgitation in three patients and acute aortic dissection in one. For aortic surgery, a composite valved conduit was used in four patients, and an aortic homograft in one. For mitral valve surgery, mechanical prostheses were used. All patients survived the primary operation. Over a mean follow-up of 17.5 patient-years (range 1 to 9 years), two patients in the infant Marfan group went on to further successful surgery (prosthetic mitral valve replacement and aortic root repair with aortic homograft) at a mean interval of 4.3 years after the initial surgery. Our results suggest that the major cardiovascular risk factors of Marfan syndrome in the young, even in those diagnosed during infancy, have been favorably changed by surgery with an encouraging medium-term outlook. The correct timing of surgery is aided by echocardiography.

Fibrillin-1 microfibrils are essential elements of the extracellular matrix serving as a scaffold for the deposition of elastin and endowing connective tissues with tensile strength and elasticity. Mutations in the fibrillin-1 gene (FBN1) are linked to Marfan syndrome (MFS), a systemic connective tissue disorder that, besides other heterogeneous symptoms, usually manifests in life-threatening aortic complications. The aortic involvement may be explained by a dysregulation of microfibrillar function and, conceivably, alterations in the microfibrils' supramolecular structure. Here, we present a nanoscale structural characterization of fibrillin-1 microfibrils isolated from two human aortic samples with different FBN1 gene mutations by using atomic force microscopy, and their comparison with microfibrillar assemblies purified from four non-MFS human aortic samples. Fibrillin-1 microfibrils displayed a characteristic "beads-on-a-string" appearance. The microfibrillar assemblies were investigated for bead geometry (height, length, and width), interbead region height, and periodicity. MFS fibrillin-1 microfibrils had a slightly higher mean bead height, but the bead length and width, as well as the interbead height, were significantly smaller in the MFS group. The mean periodicity varied around 50-52 nm among samples. The data suggest an overall thinner and presumably more frail structure for the MFS fibrillin-1 microfibrils, which may play a role in the development of MFS-related aortic symptomatology.

To assess the retinal and choroidal vasculature in patients with genetically confirmed Marfan syndrome (MfS).

One of the roles of a pediatric cardiologist who suspects or diagnoses a genetically determined connective tissue disease (e.g., Marfan, Ehlers-Danlos, and Loeys-Dietz syndromes) is to assess whether the aortic root is dilated. The aortic root diameter is affected by the patient's age, sex, and body surface area. Therefore, the aortic root diameter needs to be determined and expressed as a z-score. Calculation of the z-score is time-consuming and problematic if used infrequently. This study aimed to introduce a simple screening method for identifying aortic root dilation in children. The study population consisted of 190 children who were diagnosed with Marfan syndrome or Marfan-like disorders. The aortic root ratio (ARr) was formulated. The value of the ARr was compared in each patient with the results in z-scores, which were obtained using on-line calculators based on the most widespread nomograms. The optimal cut-off value of the ARr was ≥ 18.7. At this cut-off point, the sensitivity of the ARr ranged from 88.3% to 100% and the specificity ranged from 94% to 97.8%. All of the patients in whom the ARr failed to identify aortic root dilation were also divergently classified by different nomograms. At the ARr cut-off point of ≥ 18.0, a sensitivity of 100% was achieved for all nomograms with minimal reduction in specificity. The ARr allows for rapid and precise screening for aortic root dilation in children. Unlike classic analysis, the ARr does not require nomograms or on-line calculations.

Marfan syndrome (MFS) is a pleiotropic genetic disorder with major features in cardiovascular, ocular and skeletal systems, associated with large clinical variability. Numerous studies reveal an involvement of TGF-β signaling. However, the contribution of tissue inflammation is not addressed so far.

Marfan syndrome is a common autosomal dominant hereditary connective tissue disorder. There is no cure for Marfan syndrome currently. Next-generation sequencing (NGS) technology is efficient to identify genetic lesions at the exome level. Here we carried out exome sequencing of two Marfan syndrome patients. Further Sanger sequencing validation in other five members from the same family was also implemented to confirm new variants which may contribute to the pathogenesis of the disease. Two new variants, including one nonsense SNP in the Marfan syndrome gene FBN1 and one missense mutation in exon 15 of LRP1, which may be related to the phenotype of the patients were identified. The exome sequencing analysis provides us a new insight into the molecular events governing pathogenesis of Marfan syndrome.

Vascular progenitor cells (VPCs) present in the adventitia of the vessel wall play a critical role in the regulation of vascular repair following injury. This study aimed to assess the function of VPCs isolated from patients with Marfan syndrome (MFS). VPCs were isolated from control and MFS donors and characterized. Compared with control-VPCs, MFS-VPCs exhibited cellular senescence as demonstrated by increased cell size, higher SA-β-gal activity and elevated levels of p53 and p21. RNA sequencing showed that several cellular process-related pathways including cell cycle and cellular senescence were significantly enriched in MFP-VPCs. Notably, the expression level of TGF-β1 was much higher in MFS-VPCs than control-VPCs. Treatment of control-VPCs with TGF-β1 significantly enhanced mitochondrial reactive oxidative species (ROS) and induced cellular senescence whereas inhibition of ROS reversed these effects. MFS-VPCs displayed increased mitochondrial fusion and decreased mitochondrial fission. Treatment of control-VPCs with TGF-β1 increased mitochondrial fusion and reduced mitochondrial fission. Nonetheless, treatment of mitofusin2 (Mfn2)-siRNA inhibited TGF-β1-induced mitochondrial fusion and cellular senescence. Furthermore, TGF-β1-induced mitochondrial fusion was mediated by the AMPK signalling pathway. Our study shows that TGF-β1 induces VPC senescence in patients with MFS by mediating mitochondrial dynamics via the AMPK signalling pathway.

Marfan syndrome (MFS) is a connective tissue disorder caused by mutations in FBN1 gene, which encodes a key extracellular matrix protein FIBRILLIN-1. The haplosufficiency of FBN1 has been implicated in pathogenesis of MFS with manifestations primarily in cardiovascular, muscular, and ocular tissues. Due to limitations in animal models to study the late-onset diseases, human pluripotent stem cells (PSCs) offer a homogeneic tool for dissection of cellular and molecular pathogenic mechanism for MFS in vitro. Here, we first derived induced PSCs (iPSCs) from a MFS patient with a FBN1 mutation and corrected the mutation, thereby generating an isogenic "gain-of-function" control cells for the parental MFS iPSCs. Reversely, we knocked out FBN1 in both alleles in a wild-type (WT) human embryonic stem cell (ESC) line, which served as a loss-of-function model for MFS with the WT cells as an isogenic control. Mesenchymal stem cells derived from both FBN1-mutant iPSCs and -ESCs demonstrated reduced osteogenic differentiation and microfibril formation. We further demonstrated that vascular smooth muscle cells derived from FBN1-mutant iPSCs showed less sensitivity to carbachol as demonstrated by contractility and Ca2+ influx assay, compared to the isogenic controls cells. These findings were further supported by transcriptomic anaylsis of the cells. Therefore, this study based on both gain- and loss-of-function approaches confirmed the pathogenetic role of FBN1 mutations in these MFS-related phenotypic changes.

Background: Pathogenic variants in TGFBR1, TGFBR2 and SMAD3 genes cause Loeys-Dietz syndrome, and pathogenic variants in FBN1 cause Marfan syndrome. Despite their similar phenotypes, both syndromes may have different cardiovascular outcomes. Methods: Three expert centers performed a case-matched comparison of cardiovascular outcomes. The Loeys-Dietz group comprised 43 men and 40 women with a mean age of 34 ± 18 years. Twenty-six individuals had pathogenic variants in TGFBR1, 40 in TGFBR2, and 17 in SMAD3. For case-matched comparison we used 83 age and sex-frequency matched individuals with Marfan syndrome. Results: In Loeys-Dietz compared to Marfan syndrome, a patent ductus arteriosus (p = 0.014) was more prevalent, the craniofacial score was higher (p < 0.001), the systemic score lower (p < 0.001), and mitral valve prolapse less frequent (p = 0.003). Mean survival for Loeys-Dietz and Marfan syndrome was similar (75 ± 3 versus 73 ± 2 years; p = 0.811). Cardiovascular outcome was comparable between Loeys-Dietz and Marfan syndrome, including mean freedom from proximal aortic surgery (53 ± 4 versus 48 ± 3 years; p = 0.589), distal aortic repair (72 ± 3 versus 67 ± 2 years; p = 0.777), mitral valve surgery (75 ± 4 versus 65 ± 3 years; p = 0.108), and reintervention (20 ± 3 versus 14 ± 2 years; p = 0.112). In Loeys-Dietz syndrome, lower age at initial presentation predicted proximal aortic surgery (HR = 0.748; p < 0.001), where receiver operating characteristic analysis identified ≤33.5 years with increased risk. In addition, increased aortic sinus diameters (HR = 6.502; p = 0.001), and higher systemic score points at least marginally (HR = 1.175; p = 0.065) related to proximal aortic surgery in Loeys-Dietz syndrome. Conclusions: Cardiovascular outcome of Loeys-Dietz syndrome was comparable to Marfan syndrome, but the severity of systemic manifestations was a predictor of proximal aortic surgery.

Marfan syndrome (MFS) is an inherited and systemic disorder. It has been reported that mutations in the fibrillin‑1 gene (FBN1) account for ~90% of autosomal dominant cases of MFS. This study was conducted to screen mutations of FBN1 in a Chinese family with autosomal dominant MFS; four individuals including two patients with MFS were recruited. The family members underwent complete physical, cardiovascular and ophthalmologic examinations. Genomic DNA samples were collected from the family along with 383 unrelated healthy subjects. FBN1 coding regions were amplified by polymerase chain reaction and analyzed by direct sequencing. SIFT and PolyPhen‑2 were used to predict the possible structural and functional alterations of the protein. A novel heterozygous mutation c.1708 T>G (p.C570G) in exon 14 was identified, which led to a substitution of cysteine by glycine at codon 570 (p.C570G). The mutation was identified as being associated with the MFS phenotype in the affected members of this family. However, the unaffected family members and the 383 normal controls lacked the mutation. Multiple sequence alignment of the human FBN1 protein revealed that this novel mutation occurred within a highly conserved region of the FBN1 protein across different species and may induce structural alterations in this functional domain. The spectrum of MFS‑associated mutations in the FBN1 gene has been enriched from this study; this may improve understanding of the molecular pathogenesis and clinical diagnosis of MFS.

Marfan syndrome is a genetic connective tissue disorder affecting skeletal, ocular, and cardiovascular organ systems. Previous research found that pathogenic variants clustered in exons 24-32 of fibrillin-1 (FBN1) gene result in more severe clinical phenotypes. Furthermore, genotype-phenotype correlation studies suggested that more severe cardiovascular phenotypes were related to variants held responsible for haploinsufficiency. Our objective was to analyze the differences in clinical manifestations and genotypes of individuals with early-onset Marfan syndrome and to assess their impact on management strategies.

According to previous studies, aortic diameter alone seems to be insufficient to predict the event of aortic dissection in Marfan syndrome (MFS). Determining the optimal schedule for preventive aortic root replacement (ARR) aortic growth rate is of importance, as well as family history, however, none of them appear to be decisive. Thus, the aim of this study was to search for potential predictors of aortic dissection in MFS.

Mutations in the FBN1 gene, which encodes fibrillin-1, cause Marfan syndrome (MFS) and have been associated with a wide range of milder, overlap phenotypes. The factors that modulate phenotypic severity, both between and within families, remain to be determined. This study examines the relationship between the FBN1 genotype and phenotype in families with extremely mild phenotypes and in those that show striking clinical variation among apparently affected individuals. In one family, clinically similar but etiologically distinct disorders are segregating independently. In another, somatic mosaicism for a mutant FBN1 allele is associated with subdiagnostic manifestations, whereas germ-line transmission of the identical mutation causes severe and rapidly progressive disease. A third family cosegregates mild mitral valve prolapse syndrome with a mutation in FBN1 that can be functionally distinguished from those associated with the classic MFS phenotype. These data have immediate relevance for the diagnostic and prognostic counseling of patients and their family members.

The transforming growth factor-β (TGFβ) family plays an important role in many developmental processes and when mutated often contributes to various diseases. Marfan syndrome is a genetic disease with an occurrence of approximately 1 in 5,000. The disease is caused by mutations in fibrillin, which lead to an increase in TGFβ ligand activity, resulting in abnormalities of connective tissues which can be life-threatening. Mutations in other components of TGFβ signaling (receptors, Smads, Schnurri) lead to similar diseases with attenuated phenotypes relative to Marfan syndrome. In particular, mutations in TGFβ receptors, most of which are clustered at the C-terminal end, result in Marfan-like (MFS-like) syndromes. Even though it was assumed that many of these receptor mutations would reduce or eliminate signaling, in many cases signaling is active. From our previous studies on receptor trafficking in C. elegans, we noticed that many of these receptor mutations that lead to Marfan-like syndromes overlap with mutations that cause mis-trafficking of the receptor, suggesting a link between Marfan-like syndromes and TGFβ receptor trafficking. To test this hypothesis, we introduced three of these key MFS and MFS-like mutations into the C. elegans TGFβ receptor and asked if receptor trafficking is altered. We find that in every case studied, mutated receptors mislocalize to the apical surface rather than basolateral surface of the polarized intestinal cells. Further, we find that these mutations result in longer animals, a phenotype due to over-stimulation of the nematode TGFβ pathway and, importantly, indicating that function of the receptor is not abrogated in these mutants. Our nematode models of Marfan syndrome suggest that MFS and MFS-like mutations in the type II receptor lead to mis-trafficking of the receptor and possibly provides an explanation for the disease, a phenomenon which might also occur in some cancers that possess the same mutations within the type II receptor (e.g. colon cancer).

The present study aimed to investigate the ocular characteristics of Chinese patients with Marfan syndrome (MFS) and to evaluate the sensitivity and specificity of ocular parameters in distinguishing MFS from ectopia lentis.

Marfan syndrome (MFS) is an autosomal dominant heritable disorder of fibrillin-1 (FBN1) with predominantly ocular, cardiovascular, and musculoskeletal manifestations that has a population prevalence of approximately 1 in 5-10,000 (Chiu et al. Mayo Clin Proc. 89(1):34-42, 146, Dietz 3, Loeys et al. J Med Genet. 47(7):476-85, 4).

Patients with Marfan syndrome (MFS) develop thoracic aortic aneurysms as the aorta presents excessive elastin breaks, fibrosis, and vascular smooth muscle cell (vSMC) death due to mutations in the FBN1 gene. Despite elaborate vSMC to aortic endothelial cell (EC) signaling, the contribution of ECs to the development of aortic pathology remains largely unresolved. The aim of this study is to investigate the EC properties in Fbn1C1041G/+ MFS mice. Using en face immunofluorescence confocal microscopy, we showed that EC alignment with blood flow was reduced, EC roundness was increased, individual EC surface area was larger, and EC junctional linearity was decreased in aortae of Fbn1C1041G/+ MFS mice. This modified EC phenotype was most prominent in the ascending aorta and occurred before aortic dilatation. To reverse EC morphology, we performed treatment with resveratrol. This restored EC blood flow alignment, junctional linearity, phospho-eNOS expression, and improved the structural integrity of the internal elastic lamina of Fbn1C1041G/+ mice. In conclusion, these experiments identify the involvement of ECs and underlying internal elastic lamina in MFS aortic pathology, which could act as potential target for future MFS pharmacotherapies.

Blood flow dynamics make it possible to better understand the development of aortopathy and cardiovascular events in patients with Marfan syndrome (MFS). Aortic 3D blood flow characteristics were investigated in relation to aortic geometry in children and adolescents with MFS.