Fibrillin-1 regulates endothelial sprouting during angiogenesis.

Fibrillin-1 is an extracellular matrix protein that assembles into microfibrils which provide critical functions in large blood vessels and other tissues. Mutations in the fibrillin-1 gene are associated with cardiovascular, ocular, and skeletal abnormalities in Marfan syndrome. Here, we reveal that fibrillin-1 is critical for angiogenesis which is compromised by a typical Marfan mutation. In the mouse retina vascularization model, fibrillin-1 is present in the extracellular matrix at the angiogenic front where it colocalizes with microfibril-associated glycoprotein-1, MAGP1. In Fbn1C1041G/+ mice, a model of Marfan syndrome, MAGP1 deposition is reduced, endothelial sprouting is decreased, and tip cell identity is impaired. Cell culture experiments confirmed that fibrillin-1 deficiency alters vascular endothelial growth factor-A/Notch and Smad signaling which regulate the acquisition of endothelial tip cell/stalk cell phenotypes, and we showed that modulation of MAGP1 expression impacts these pathways. Supplying the growing vasculature of Fbn1C1041G/+ mice with a recombinant C-terminal fragment of fibrillin-1 corrects all defects. Mass spectrometry analyses showed that the fibrillin-1 fragment alters the expression of various proteins including ADAMTS1, a tip cell metalloprotease and matrix-modifying enzyme. Our data establish that fibrillin-1 is a dynamic signaling platform in the regulation of cell specification and matrix remodeling at the angiogenic front and that mutant fibrillin-1-induced defects can be rescued pharmacologically using a C-terminal fragment of the protein. These findings, identify fibrillin-1, MAGP1, and ADAMTS1 in the regulation of endothelial sprouting, and contribute to our understanding of how angiogenesis is regulated. This knowledge may have critical implications for people with Marfan syndrome.

National registry insights on genetic aortopathies and thoracic endovascular aortic interventions.

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) in patients with genetic aortopathies (GA) is controversial, given concerns of durability. We describe characteristics and outcomes after TEVAR in patients with GA. METHODS: All patients undergoing TEVAR between 2010 and 2023 in the Vascular Quality Iniatitive were identified and categorized as having a GA or not. Demographics, baseline, and procedural characteristics were compared among groups. Multivariable logistic regression was used to evaluate the independent association of GA with postoperative outcomes. Kaplan-Meier methods and multivariable Cox regression analyses were used to evaluate 5-year survival and 2-year reinterventions. RESULTS: Of 19,340 patients, 304 (1.6%) had GA (87% Marfan syndrome, 9% Loeys-Dietz syndrome, and 4% vascular Ehlers-Danlos syndrome). Compared with patients without GA, patients with GA were younger (50 years [interquartile range, 37-72 years] vs 70 years [interquartile range, 61-77 years]), more often presented with acute dissection (28% vs 18%), postdissection aneurysm (48% vs 17%), had a symptomatic presentation (50% vs 39%), and were less likely to have degenerative aneurysms (18% vs 47%) or penetrating aortic ulcer (and intramural hematoma) (3% vs 13%) (all P < .001). Patients with GA were more likely to have prior repair of the ascending aorta/arch (open, 56% vs 11% [P < .001]; endovascular, 5.6% vs 2.1% [P = .017]) or the descending thoracic aorta (open, 12% vs 2% [P = .007]; endovascular, 8.2% vs 3.6% [P = .011]). No significant differences were found in prior abdominal suprarenal repairs; however, patients with GA had more prior open infrarenal repairs (5.3% vs 3.2%), but fewer prior endovascular infrarenal repairs (3.3% vs 5.5%) (all P < .05). After adjusting for demographics, comorbidities, and disease characteristics, patients with GA had similar odds of perioperative mortality (4.6% vs 7.0%; adjusted odds ratio [aOR], 1.1; 95% confidence interval [CI], 0.57-1.9; P = .75), any in-hospital complication (26% vs 23%; aOR, 1.24; 95% CI, 0.92-1.6; P = .14), or in-hospital reintervention (13% vs 8.3%; aOR, 1.25; 95% CI, 0.84-1.80; P = .25) compared with patients without GA. However, patients with GA had a higher likelihood of postoperative vasopressors (33% vs 27%; aOR, 1.44; 95% CI, 1.1-1.9; P = .006) and transfusion (25% vs 23%; aOR, 1.39; 95% CI, 1.03-1.9; P = .006). The 2-year reintervention rates were higher in patients with GA (25% vs 13%; adjusted hazard ratio, 1.99; 95% CI, 1.4-2.9; P < .001), but 5-year survival was similar (81% vs 74%; adjusted hazard ratio, 1.02; 95% CI, 0.70-1.50; P = .1). CONCLUSIONS: TEVAR for patients with GA seemed to be safe initially, with similar odds for in-hospital complications, in-hospital reinterventions, and perioperative mortality, as well as similar hazards for 5-year mortality compared with patients without GA. However, patients with GA had higher 2-year reintervention rates. Future studies should assess long-term durability after TEVAR compared with the recommended open repair to appropriately weigh the risks and benefits of endovascular treatment in patients with GA.

A novel de novo intragenic duplication in FBN1 associated with early-onset Marfan syndrome in a 16-month-old: A case report and review of the literature.

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder due to pathogenic variants in Fibrillin-1 (FBN1) affecting nearly one in every 10,000 individuals. We report a 16-month-old female with early-onset MFS heterozygous for an 11.2 kb de novo duplication within the FBN1 gene. Tandem location of the duplication was further confirmed by optical genome mapping in addition to genetic sequencing and chromosomal microarray. This is the third reported case of a large multi-exon duplication in FBN1, and the only one confirmed to be in tandem. As the vast majority of pathogenic variants associated with MFS are point mutations, this expands the landscape of known FBN1 pathogenic variants and supports consistent use of genetic testing strategies that can detect large, indel-type variants.

Occurrence of cancer in Marfan syndrome: Report of two patients with neuroblastoma and review of the literature.

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by pathogenic variants in FBN1, with a hitherto unknown association with cancer. Here, we present two females with MFS who developed pediatric neuroblastoma. Patient 1 presented with neonatal MFS and developed an adrenal neuroblastoma with unfavorable tumor genetics at 10 months of age. Whole genome sequencing revealed a germline de novo missense FBN1 variant (NP_000129.3:p.(Asp1322Asn)), resulting in intron 32 inclusion and exon 32 retention. Patient 2 was diagnosed with classic MFS, caused by a germline de novo frameshift variant in FBN1 (NP_000129.3:p.(Cys805Ter)). At 18 years, she developed high-risk neuroblastoma with a somatic ALK pathogenic variant (NP_004295.2:p.(Arg1275Gln)). We identified 32 reported cases of MFS with cancer in PubMed, yet none with neuroblastoma. Among patients, we observed an early cancer onset and high frequency of MFS complications. We also queried cancer databases for somatic FBN1 variants, finding 49 alterations reported in PeCan, and variants in 2% of patients in cBioPortal. In conclusion, we report the first two patients with MFS and neuroblastoma and highlight an early age at cancer diagnosis in reported patients with MFS. Further epidemiological and functional studies are needed to clarify the growing evidence linking MFS and cancer.

Vertebral artery dissection caused by atlantoaxial dislocation in a patient with Marfan syndrome.

A small number of case reports have documented a link between atlantoaxial dislocation (AAD) and vertebral artery dissection (VAD), but this association has never been described in patients with hereditary connective tissue disorders. We present a case of an 18-year-old female patient, diagnosed with Marfan syndrome since the age of one, who underwent brain MRA for intracranial aneurysm screening revealing tortuosity of the internal carotid and vertebral arteries as well as atlantoaxial dislocation. Since the patient was asymptomatic, a wait-and-see approach was chosen, but a follow-up MRA after 18 months showed the appearance of a dissecting pseudoaneurysm of the V3 segment of the left vertebral artery. Despite the patient being still asymptomatic, it was decided to proceed with C1-C2 stabilization to prevent further vascular complications. Follow-up imaging showed realignment of the atlantoaxial joint and reduction of the dissecting pseudoaneurysm of the left vertebral artery. In our patient, screening MRA has led to the discovery of asymptomatic arterial and skeletal abnormalities which, if left untreated, might have led to severe cerebrovascular complications. Therefore, AAD correction or close monitoring with MRA should be provided to MFS patients with this craniovertebral junction anomaly, even if asymptomatic.

Inhibition of IL11 Signaling Reduces Aortic Pathology in Murine Marfan Syndrome.

BACKGROUND: Marfan syndrome (MFS) is associated with TGF (transforming growth factor) ß-stimulated ERK (extracellular signal-regulated kinase) activity in vascular smooth muscle cells (VSMCs), which adopt a mixed synthetic/contractile phenotype. In VSMCs, TGFß induces IL (interleukin) 11) that stimulates ERK-dependent secretion of collagens and MMPs (matrix metalloproteinases). Here, we examined the role of IL11 in the MFS aorta. METHODS: We used echocardiography, histology, immunostaining, and biochemical methods to study aortic anatomy, physiology, and molecular endophenotypes in Fbn1C1041G/+ mice, an established murine model of MFS (mMFS). mMFS mice were crossed to an IL11-tagged EGFP (enhanced green fluorescent protein; Il11EGFP/+) reporter strain or to a strain deleted for the IL11 receptor (Il11ra1-/-). In therapeutic studies, mMFS were administered an X209 (neutralizing antibody against IL11RA [IL11 receptor subunit alpha]) or IgG for 20 weeks and imaged longitudinally. RESULTS: IL11 mRNA and protein were elevated in the aortas of mMFS mice, as compared to controls. mMFS mice crossed to Il11EGFP/+ mice had increased IL11 expression in VSMCs, notably in the aortic root and ascending aorta. As compared to the mMFS parental strain, double mutant mMFS:Il11ra1-/- mice had reduced aortic dilatation and exhibited lesser fibrosis, inflammation, elastin breaks, and VSMC loss, which was associated with reduced aortic COL1A1 (collagen type I alpha 1 chain), IL11, MMP2/9, and phospho-ERK expression. To explore therapeutic targeting of IL11 signaling in MFS, we administered either a neutralizing antibody against IL11RA (X209) or an IgG control. After 20 weeks of antibody administration, as compared to IgG, mMFS mice receiving X209 had reduced thoracic and abdominal aortic dilation as well as lesser fibrosis, inflammation, elastin breaks, and VSMC loss. By immunoblotting, X209 was shown to reduce aortic COL1A1, IL11, MMP2/9, and phospho-ERK expression. CONCLUSIONS: In MFS, IL11 is upregulated in aortic VSMCs to cause ERK-related thoracic aortic dilatation, inflammation, and fibrosis. Therapeutic inhibition of IL11, imminent in clinical trials, might be considered as a new approach in MFS.

Smooth Muscle Cell Klf4 Expression Is Not Required for Phenotype Modulation or Aneurysm Formation in Marfan Syndrome Mice-Brief Report.

BACKGROUND: Smooth muscle cell (SMC) phenotypic reprogramming toward a mixed synthetic-proteolytic state is a central feature of aortic root aneurysm in Marfan syndrome (MFS). Previous work identified Klf4 as a potential mediator of SMC plasticity in MFS. METHODS: MFS (Fbn1C1041G/+) mouse strains with an inducible vascular SMC fluorescent reporter (MFSSMC) with or without SMC-specific deletion of Klf4 exons 2 to 3 (MFSSMC-Klf4Δ) were generated. Simultaneous SMC tracing and Klf4 loss-of-function (Klf4Δ mice) was induced at 6 weeks of age. Aneurysm growth was assessed via serial echocardiography (4-24 weeks). Twenty-four-week-old mice were assessed via histology, RNA in situ hybridization, and aortic single-cell RNA sequencing. RESULTS: MFS mice demonstrated progressive aortic root dilatation compared with control (WTSMC) mice regardless of Klf4 genotype (P<0.001), but there was no difference in aneurysm growth in MFSSMC-Klf4Δ versus MFSSMC (P=0.884). Efficient SMC Klf4 deletion was confirmed via lineage-stratified genotyping, RNA in situ hybridization, and immunohistochemistry. Single-cell RNA sequencing of traced SMCs revealed a highly similar pattern of phenotype modulation marked by loss of contractile markers (eg, Myh11, Cnn1) and heightened expression of matrix genes (eg, Col1a1, Fn1) between Klf4 genotypes. Pseudotemporal quantitation of SMC dedifferentiation confirmed that Klf4 deletion did not alter the global extent of phenotype modulation, but reduced expression of 23 genes during this phenotype transition in MFSSMC-Klf4Δmice, including multiple chondrogenic genes expressed by only the most severely dedifferentiated SMCs (eg, Cytl1, Tnfrsf11b). CONCLUSIONS: Klf4 is not required to initiate SMC phenotype modulation in MFS aneurysm but may exert regulatory control over chondrogenic genes expressed in highly dedifferentiated SMCs.

Redox Dysregulation of Vascular Smooth Muscle Sirtuin-1 in Thoracic Aortic Aneurysm in Marfan Syndrome.

BACKGROUND: Thoracic aortic aneurysms (TAAs) are abnormal aortic dilatations and a major cardiovascular complication of Marfan syndrome. We previously demonstrated a critical role for vascular smooth muscle (VSM) SirT1 (sirtuin-1), a lysine deacetylase, against maladaptive aortic remodeling associated with chronic oxidative stress and aberrant activation of MMPs (matrix metalloproteinases). METHODS: In this study, we investigated whether redox dysregulation of SirT1 contributed to the pathogenesis of TAA using fibrillin-1 hypomorphic mice (Fbn1mgR/mgR), an established model of Marfan syndrome prone to aortic dissection/rupture. RESULTS: Oxidative stress markers 3-nitrotyrosine and 4-hydroxynonenal were significantly elevated in aortas of patients with Marfan syndrome. Moreover, reversible oxidative post-translational modifications (rOPTM) of protein cysteines, particularly S-glutathionylation, were dramatically increased in aortas of Fbn1mgR/mgR mice, before induction of severe oxidative stress markers. Fbn1mgR/mgR aortas and VSM cells exhibited an increase in rOPTM of SirT1, coinciding with the upregulation of acetylated proteins, an index of decreased SirT1 activity, and increased MMP2/9 activity. Mechanistically, we demonstrated that TGFß (transforming growth factor beta), which was increased in Fbn1mgR/mgR aortas, stimulated rOPTM of SirT1, decreasing its deacetylase activity in VSM cells. VSM cell-specific deletion of SirT1 in Fbn1mgR/mgR mice (SMKO-Fbn1mgR/mgR) caused a dramatic increase in aortic MMP2 expression and worsened TAA progression, leading to aortic rupture in 50% of SMKO-Fbn1mgR/mgR mice, compared with 25% of Fbn1mgR/mgR mice. rOPTM of SirT1, rOPTM-mediated inhibition of SirT1 activity, and increased MMP2/9 activity were all exacerbated by the deletion of Glrx (glutaredoxin-1), a specific deglutathionylation enzyme, while being corrected by overexpression of Glrx or of an oxidation-resistant SirT1 mutant in VSM cells. CONCLUSIONS: Our novel findings strongly suggest a causal role of S-glutathionylation of SirT1 in the pathogenesis of TAA. Prevention or reversal of SirT1 rOPTM may be a novel therapeutic strategy to prevent TAA and TAA dissection/ruptures in individuals with Marfan syndrome, for which, thus far, no targeted therapy has been developed.

IL11 (Interleukin-11) Causes Emphysematous Lung Disease in a Mouse Model of Marfan Syndrome.

BACKGROUND: Marfan Syndrome (MFS) is an inherited connective tissue disorder caused by mutations in the FBN1 (fibrillin-1) gene. Lung abnormalities are common in MFS, but their pathogenesis is poorly understood. IL11 (interleukin-11) causes aortic disease in a mouse model of MFS and was studied here in the lung. METHODS: We examined histological and molecular phenotypes in the lungs of Fbn1C1041G/+ mice (mouse model of Marfan Syndrome [mMFS]), an established mouse model of MFS. To identify IL11-expressing cells, we used immunohistochemistry on lungs of 4- and 16-week-old Fbn1C1041G/+:Il11EGFP/+ reporter mice. We studied the effects of IL11 inhibition by RT-qPCR, immunoblots and histopathology in lungs from genetic or pharmacologic models: (1) 16-week-old IL11 receptor (IL11RA) knockout mMFS mice (Fbn1C1041G/+:Il11ra1-/- mice) and (2) in mMFS mice administered IgG control or interleukin-11 receptor antibodies twice weekly from 4 to 24 weeks of age. RESULTS: mMFS lungs showed progressive loss and enlargement of distal airspaces associated with increased proinflammatory and profibrotic gene expression as well as matrix metalloproteinases 2, 9, and 12. IL11 was increased in mMFS lungs and localized to smooth muscle and endothelial cells in young mMFS mice in the Fbn1C1041G/+:Il11EGFP/+ reporter strain and in fibroblasts, in older mice. In mMFS mice, genetic (Fbn1C1041G/+:Il11ra1-/-) or pharmacologic (anti-interleukin-11 receptor) inhibition of IL11 signaling reduced lung emphysema, fibrosis, and inflammation. This protective effect was associated with reduced pathogenic ERK1/2 signaling and lower metalloproteinase 2, 9, and 12 expression. CONCLUSIONS: IL11 causes lung disease in mMFS. This reveals a shared IL11-driven disease mechanism in lung and aorta in MFS and suggests inhibition of IL11 signaling as a holistic approach for treating multiorgan morbidity in MFS.

Lineage-Specific Induced Pluripotent Stem Cell-Derived Smooth Muscle Cell Modeling Predicts Integrin Alpha-V Antagonism Reduces Aortic Root Aneurysm Formation in Marfan Syndrome Mice.

BACKGROUND: The role of increased smooth muscle cell (SMC) integrin αv signaling in Marfan syndrome (MFS) aortic aneurysm remains unclear. Herein, we examine the mechanism and potential efficacy of integrin αv blockade as a therapeutic strategy to reduce aneurysm progression in MFS. METHODS: Induced pluripotent stem cells (iPSCs) were differentiated into aortic SMCs of the second heart field (SHF) and neural crest (NC) lineages, enabling in vitro modeling of MFS thoracic aortic aneurysms. The pathological role of integrin αv during aneurysm formation was confirmed by blockade of integrin αv with GLPG0187 in Fbn1C1039G/+ MFS mice. RESULTS: iPSC-derived MFS SHF SMCs overexpress integrin αv relative to MFS NC and healthy control SHF cells. Furthermore, integrin αv downstream targets (FAK [focal adhesion kinase]/AktThr308/mTORC1 [mechanistic target of rapamycin complex 1]) were activated, especially in MFS SHF. Treatment of MFS SHF SMCs with GLPG0187 reduced p-FAK/p-AktThr308/mTORC1 activity back to control SHF levels. Functionally, MFS SHF SMCs had increased proliferation and migration compared to MFS NC SMCs and control SMCs, which normalized with GLPG0187 treatment. In the Fbn1C1039G/+ MFS mouse model, integrin αv, p-AktThr308, and downstream targets of mTORC1 proteins were elevated in the aortic root/ascending segment compared to littermate wild-type control. Mice treated with GLPG0187 (age 6-14 weeks) had reduced aneurysm growth, elastin fragmentation, and reduction of the FAK/AktThr308/mTORC1 pathway. GLPG0187 treatment reduced the amount and severity of SMC modulation assessed by single-cell RNA sequencing. CONCLUSIONS: The integrin αv-FAK-AktThr308 signaling pathway is activated in iPSC SMCs from MFS patients, specifically from the SHF lineage. Mechanistically, this signaling pathway promotes SMC proliferation and migration in vitro. As biological proof of concept, GLPG0187 treatment slowed aneurysm growth and p-AktThr308 signaling in Fbn1C1039G/+ mice. Integrin αv blockade via GLPG0187 may be a promising therapeutic approach to inhibit MFS aneurysmal growth.

Quality of life in young patients with acute type a aortic dissection in China: comparison with Marfan syndrome and non-Marfan syndrome.

BACKGROUND: There is a paucity of Chinese studies evaluating the quality of life (QoL) in young acute type A aortic dissection (AAAD) patients with Marfan syndrome. METHODS: Young adult AAAD patients (younger than 45 years old) underwent surgical treatment at our institution from January 2017 to December 2020 were consecutive enrolled. The hospital survivors completed 1 year of follow up. Patients were divided into two groups according to the presence or absence of Marfan syndrome (MFS). A 1:1 propensity score matching (PSM) with a caliper 0.2 was conducted to balance potential bias in baseline. The follow-up data were analyzed primarily for change in quality of life and anxiety status. RESULTS: After PSM, 32 comparable pairs were matched. The baseline data were comparable and postoperative complications were similar between groups. In terms of SF-36 scale, the role physical, bodily pain, role emotional and mental health subscales were no significantly improved in MFS patients over time. At 1 year after discharged, the subscale of mental health and bodily pain were significantly lower in the MFS group than in the non-MFS group. In terms of HADS assessments, the level of anxiety in MFS patients was significantly higher than in non-MFS patients at 1 year after discharged. CONCLUSIONS: The QoL in young AAAD patients with MFS is lower than those without MFS after surgery. This may be associated with the uncontrollable persistent chronic pain and the uncertainty and concerns for the disease's progression.

Genotype and clinical phenotype of children with Marfan syndrome in Southeastern Anatolia.

The cardinal phenotypic hallmarks of Marfan syndrome (MFS) include cardiac, ocular, and skeletal abnormalities. Since the clinical phenotype of MFS is highly heterogeneous, with certain symptoms appearing as children age, the diagnostic process and establishing a genotype-phenotype association in childhood MFS can be challenging. The lack of sufficient childhood studies also makes it difficult to interpret the subject. This study aims to evaluate the relationship between clinical symptoms used as diagnostic criteria and FBN1 variations in children with MFS. This study investigated the relationships between genotypes and phenotypes in 131 children suspected of having Marfan syndrome (MFS). Diagnosis of MFS was made according to the revised Ghent nosology. FBN1 variants were categorized based on exon regions, type of variant, and pathogenicity classes. These FBN1 variants were then correlated with the clinical manifestations including cardiovascular, ocular, facial, and skeletal abnormalities. Out of the children, 43 were diagnosed with MFS. FBN1 variant was identified in 32 (74.4%) of the MFS children. MFS diagnosis could not be made in five (15.6%) FBN1 variant-positive children. The most common cardinal finding is cardiac anomalies n = 38 (88.3%). The most common FBN1 pathogenic variant was c.1786 T > C/p.Cys596Arg n = 4 (12.5%). The distribution of pathogenic variants was as follows: 29 (90.6%) missense, 2 (6.3%) frameshift, and 1 (3.1%) nonsense. The numbers of AD and EL of the variant-positive children were 16 (50%) and 14 (43.7%), respectively. Ocular abnormalities were more common in children with FBN1-positive MFS (p = 0.009). There was no difference in the number of cardiac abnormalities between FBN1-positive and FBN1-negative MFS patients (p = 0.139).   Conclusion: This study examines the relationship between FBN1 variants and clinical features used as diagnostic criteria in MFS children. The findings emphasize the importance of long-term monitoring of heterogeneous clinical phenotypes and bioinformatic reanalysis in determining the genotype-phenotype relationship in children, as MFS symptoms can vary with age. What is Known: • Marfan syndrome has highly variable phenotypic heterogeneity. • The genotype-phenotype relationship in childhood Marfan syndrome is not clear enough due to the variation in the time of onset of the findings. What is New: • This article provides regional data for the field of research on genotype-phenotype relationships in childhood Marfan syndrome. • Long-term follow-up of clinical findings and bioinformatics reanalysis is an important requirement for a well-established genotype-phenotype relationship in childhood Marfan syndrome.

Physical fitness in children with Marfan and Loeys-Dietz syndrome: associations between cardiovascular parameters, systemic manifestations, fatigue, and pain.

Children with Marfan (MFS) and Loeys-Dietz syndrome (LDS) report limitations in physical activities, sports, school, leisure, and work participation in daily life. This observational, cross-sectional, multicenter study explores associations between physical fitness and cardiovascular parameters, systemic manifestations, fatigue, and pain in children with MFS and LDS. Forty-two participants, aged 6-18 years (mean (SD) 11.5(3.7)), diagnosed with MFS (n = 36) or LDS (n = 6), were enrolled. Physical fitness was evaluated using the Fitkids Treadmill Test's time to exhaustion (TTE) outcome measure. Cardiovascular parameters (e.g., echocardiographic parameters, aortic surgery, cardiovascular medication) and systemic manifestations (systemic score of the revised Ghent criteria) were collected. Pain was obtained by visual analog scale. Fatigue was evaluated by PROMIS® Fatigue-10a-Pediatric-v2.0-short-form and PROMIS® Fatigue-10a-Parent-Proxy-v2.0-short-form. Multivariate linear regression analyses explored associations between physical fitness (dependent variable) and independent variables that emerged from the univariate linear regression analyses (criterion p < .05). The total group (MFS and LDS) and the MFS subgroup scored below norms on physical fitness TTE Z-score (mean (SD) -3.1 (2.9); -3.0 (3.0), respectively). Univariate analyses showed associations between TTE Z-score aortic surgery, fatigue, and pain (criterion p < .05). Multivariate analyses showed an association between physical fitness and pediatric self-reported fatigue that explained 48%; 49%, respectively, of TTE Z-score variance (F (1,18) = 18.6, p ≤ .001, r2 = .48; F (1,15) = 16,3, p = .01, r2 = .49, respectively).    Conclusions: Physical fitness is low in children with MFS or LDS and associated with self-reported fatigue. Our findings emphasize the potential of standardized and tailored exercise programs to improve physical fitness and reduce fatigue, ultimately enhancing the physical activity and sports, school, leisure, and work participation of children with MFS and LDS. What is Known: • Marfan and Loeys-Dietz syndrome are heritable connective tissue disorders and share cardiovascular and systemic manifestations. • Children with Marfan and Loeys-Dietz syndrome report increased levels of disability, fatigue and pain, as well as reduced levels of physical activity, overall health and health-related quality of life. What is New: • Physical fitness is low in children with Marfan and Loeys-Dietz syndrome and associated with self-reported fatigue. • Our findings emphasize the potential of standardized and tailored exercise programs to improve physical fitness and reduce fatigue, ultimately enhancing the physical activity and sports, school, leisure, and work participation of children with Marfan and Loeys-Dietz syndrome.

Neurological abnormalities in individuals with Marfan syndrome: results from a genetically confirmed Italian cohort.

BACKGROUND AND AIMS: Neurological abnormalities have been frequently reported in individuals with Marfan Syndrome (MFS). However, available data relies solely on retrospective studies predating current diagnostic criteria. METHODS: Cross-sectional study comprehensively investigating neurological abnormalities within a prospective cohort of adults (≥ 18 years) with genetically confirmed MFS referred to an Italian hub center for heritable connective tissue diseases (Jan. 1st - Nov. 15th, 2021). RESULTS: We included a total of 38 individuals (53% female). The commonest neurological symptom was migraine (58%), usually without aura (73%). Neuropsychological testing was generally unremarkable, whilst anxiety and depression were highly prevalent within our cohort (42% and 34%, respectively). The most frequent brain parenchymal abnormality was the presence of cortico-subcortical hypointense spots on brain MRI T2* Gradient-Echo sequences (39%), which were found only in patients with a prior history of aortic surgery. Migraineurs had a higher frequency of brain vessels tortuosity vs. individuals without migraine (73% vs. 31%; p = 0.027) and showed higher average and maximum tortuosity indexes in both anterior and posterior circulation brain vessels (all p < 0.05). At univariate regression analysis, the presence of brain vessels tortuosity was significantly associated with a higher risk of migraine (OR 5.87, CI 95% 1.42-24.11; p = 0.014). CONCLUSIONS: Our study confirms that neurological abnormalities are frequent in individuals with MFS. While migraine appears to be associated with brain vessels tortuosity, brain parenchymal abnormalities are typical of individuals with a prior history of aortic surgery. Larger prospective studies are needed to understand the relationship between parenchymal abnormalities and long-term cognitive outcomes.

Overcoming challenges associated with identifying FBN1 deep intronic variants through whole-genome sequencing.

BACKGROUND: Marfan syndrome (MFS), caused by pathogenic variants of FBN1 (fibrillin-1), is a systemic connective tissue disorder with variable phenotypes and treatment responsiveness depending on the variant. However, a significant number of individuals with MFS remain genetically unexplained. In this study, we report novel pathogenic intronic variants in FBN1 in two unrelated families with MFS. METHODS: We evaluated subjects with suspected MFS from two unrelated families using Sanger sequencing or multiplex ligation-dependent probe amplification of FBN1 and/or panel-based next-generation sequencing. As no pathogenic variants were identified, whole-genome sequencing was performed. Identified variants were analyzed by reverse transcription-PCR and targeted sequencing of FBN1 mRNA harvested from peripheral blood or skin fibroblasts obtained from affected probands. RESULTS: We found causative deep intronic variants, c.6163+1484A>T and c.5788+36C>A, in FBN1. The splicing analysis revealed an insertion of in-frame or out-of-frame intronic sequences of the FBN1 transcript predicted to alter function of calcium-binding epidermal growth factor protein domain. Family members carrying c.6163+1484A>T had high systemic scores including prominent skeletal features and aortic dissection with lesser aortic dilatation. Family members carrying c.5788+36C>A had more severe aortic root dilatation without aortic dissection. Both families had ectopia lentis. CONCLUSION: Variable penetrance of the phenotype and negative genetic testing in MFS families should raise the possibility of deep intronic FBN1 variants and the need for additional molecular studies. This study expands the mutation spectrum of FBN1 and points out the importance of intronic sequence analysis and the need for integrative functional studies in MFS diagnosis.

Cervical kyphosis correction in Marfan syndrome: our experience and literature review.

BACKGROUND: Spinal deformities are common in Marfan syndrome (MFS). They usually involve the thoraco-lumbar spine but rarely involves the cervical spine. Kyphosis is the common spine deformity of the cervical spine and mandates surgical correction as they are at risk of neurological deterioration since they are refractory to conservative management. Few studies of surgical correction of spine deformity included cervical deformity. OBJECTIVES: To analyze the challenges faced during surgery, clinical and radiological outcome, and complications following surgical correction for cervical kyphosis in Marfan syndrome. METHODS: We identified that 5 patients with a diagnosis of MFS with cervical kyphosis who underwent fusion surgery between the years 2010 and 2022 were reviewed, retrospectively. We analyzed the demographic details, radiological parameters, operative variables (blood loss and nuances), perioperative complications, length of stay, clinical and radiological outcome, and complications following fusion surgery for cervical kyphosis in MFS. RESULTS: The mean age of patients was 16.6 ± 4.72 years (range, 12-23 years). The average kyphotic vertebra involved is 3 ± 0.7 bodies (range 2-4) with 2 patients with thoracic deformity. All patients underwent surgical deformity correction. All patients improved clinically with Nurick grade (pre vs. post: 3.4 vs. 2.2) and mJOA (pre vs. post: 8.2 vs. 12.6). There was significant deformity correction from 37.48° to 9.1°. Mean blood loss encountered was 900 ± 173.2 ml. Perioperative complications: wound complication with CSF leak (1). Late complications: ventilator dependence (1) and junctional kyphosis (1). Mean length of hospital stay was 103 ± 178.9 days. All patients were doing symptomatically better after mean follow-up of 58 ± 28.32 months. One patient is bedridden and hospitalized. CONCLUSION: Cervical kyphosis is a rare spine deformity in patients with MFS, and they usually present with neurological deterioration mandating surgical correction. Multidisciplinary approach (pediatrics, genetics and cardiology) is required for systematic evaluation of these patients. They should be evaluated with necessary imaging to rule out associated spinal deformity (atlanto-axial subluxation, scoliosis, and intraspinal pathology like ductal ectasia). Our results suggest better surgical outcome in terms of low operative complications with neurologic improvement in MFS patients. These patients require regular follow-up to identify late complications (instrument failure, non-union, and pseudarthrosis).

Quantitative measurement of dural ectasia: associations with clinical and genetic characteristics in Marfan syndrome.

PURPOSE: Dural ectasia (DE) may significantly impact Marfan syndrome (MFS) patients' quality of life due to chronic lower back pain, postural headache and urinary disorders. We aimed to evaluate the association of quantitative measurements of DE, and their evolution over time, with demographic, clinical and genetic characteristics in a cohort of MFS patients. METHODS: We retrospectively included 88 consecutive patients (39% females, mean age 37.1 ± 14.2 years) with genetically confirmed MFS who underwent at least one MRI or CT examination of the lumbosacral spine. Vertebral scalloping (VS) and dural sac ratio (DSR) were calculated from L3 to S3. Likely pathogenic or pathogenic FBN1 variants were categorized as either protein-truncating or in-frame. The latter were further classified according to their impact on the cysteine content of fibrillin-1. RESULTS: Higher values of the systemic score (revised Ghent criteria) were associated with greater DSR at lumbar (p < 0.001) and sacral (p = 0.021) levels. Patients with protein-truncating variants exhibited a greater annual increase in lumbar (p = 0.039) and sacral (p = 0.048) DSR. Mutations affecting fibrillin-1 cysteine content were linked to higher VS (p = 0.009) and DSR (p = 0.038) at S1, along with a faster increase in VS (p = 0.032) and DSR (p = 0.001) in the lumbar region. CONCLUSION: Our study shed further light on the relationship between genotype, dural pathology, and the overall clinical spectrum of MFS. The identification of protein-truncating variants and those impacting cysteine content may therefore suggest closer patient monitoring, in order to address potential complications associated with DE.

Human Genetics of Ventricular Septal Defect.

Ventricular septal defects (VSDs) are recognized as one of the commonest congenital heart diseases (CHD), accounting for up to 40% of all cardiac malformations, and occur as isolated CHDs as well as together with other cardiac and extracardiac congenital malformations in individual patients and families. The genetic etiology of VSD is complex and extraordinarily heterogeneous. Chromosomal abnormalities such as aneuploidy and structural variations as well as rare point mutations in various genes have been reported to be associated with this cardiac defect. This includes both well-defined syndromes with known genetic cause (e.g., DiGeorge syndrome and Holt-Oram syndrome) and so far undefined syndromic forms characterized by unspecific symptoms. Mutations in genes encoding cardiac transcription factors (e.g., NKX2-5 and GATA4) and signaling molecules (e.g., CFC1) have been most frequently found in VSD cases. Moreover, new high-resolution methods such as comparative genomic hybridization enabled the discovery of a high number of different copy number variations, leading to gain or loss of chromosomal regions often containing multiple genes, in patients with VSD. In this chapter, we will describe the broad genetic heterogeneity observed in VSD patients considering recent advances in this field.

Echogenomics: Echocardiography in Heritable Aortopathies.

PURPOSE OF REVIEW: The aim of this article is to review the current echocardiographic considerations in the diagnosis and monitoring of patients with inherited aortopathies. RECENT FINDINGS: Aortic dilation is a key feature in heritable aortopathies, and dissection is a leading cause of morbidity and mortality. New genetic and histopathologic findings are helpful in better understanding these conditions. Non-invasive imaging modalities, including echocardiogram, computerized tomography, and magnetic resonance imaging, are essential in monitoring these patients, as well as providing new prognostic factors of arterial stiffness that may help with risk stratification in the future. Diagnosis of heritable aortopathies should be considered with identification of aortic root dilation, particularly in children and young adults, or when there is a family history of aortic disease. Recent adult consensus guidelines highlight the importance of underlying genotype and phenotypic features when considering prophylactic surgical intervention. There are currently no consensus pediatric guidelines.

Extracardiac Manifestations Fail to Predict the Severity of Cardiac Phenotype in Children and Young Adults with Marfan Syndrome.

We performed a secondary analysis of the Pediatric Heart Network (PHN) Marfan Trial public-use database to evaluate associations between extracardiac features and cardiac and aortic phenotypes in study participants. Aortic aneurysm phenotype was defined as aortic root Z-score ≥4.5, aortic root growth rate ≥75th percentile, aortic dissection, and aortic surgery. Severe cardiac phenotype was defined as aortic dissection, aortic Z-score ≥4.5, aortic valve surgery, at least moderate mitral regurgitation, mitral valve surgery, left ventricular dysfunction, or death. Extracardiac manifestations were characterized by specific organ system involvement and by a novel aggregate extracardiac score (AES) that was created for this study based on the original Ghent nosology. Mixed effects logistic regression analysis compared AES and systems involvement to outcomes. Of 608 participants (60% male), the median age at enrollment was 10.8 years (interquartile range: 6, 15.4). Aortic aneurysm phenotype was observed in 71% of participants and 64% had severe cardiac phenotype. On univariable analysis, skeletal (OR: 1.95, 95% CI: 1.01, 3.72; p = 0.05), skin manifestation (OR: 1.62, 95% CI: 1.13, 2.34; p = 0.01) and AES (OR: 1.17, 95% CI: 1.02, 1.34; p = 0.02) were associated with aortic aneurysm phenotype but were not significant in multivariable analysis. There was no association between extracardiac manifestations and severe cardiac phenotype. Thus, the severity of cardiac manifestations in Marfan syndrome (MFS) was independent of extracardiac phenotype and AES. Severity of extracardiac involvement did not appear to be a useful clinical marker for cardiovascular risk-stratification in this cohort of children and young adults with MFS.