Marfan Syndrome: A Clinical Update

Increased Rate of Complications Following Total Knee Arthroplasty in Patients Who Have Marfan Syndrome

BACKGROUND

Outcomes of Marfan syndrome (MFS) patients after total knee arthroplasty (TKA) are poorly documented in the literature. The purpose of this study was to evaluate MFS as a potential risk factor for complications after TKA.

METHODS

Using a national private payer insurance database from 2010 to 2022, MFS patients undergoing primary TKA were identified and compared to 10:1 matched controls based on age, sex, obesity, diabetes mellitus, and a comorbidity index. A total of 4,092 patients undergoing primary TKA were analyzed, of which 372 had MFS. Multivariable logistic regression analyses were done for medical complications up to 90 days and surgical complications up to 2 years. 90-day emergency department-visits and inpatient readmissions were also documented.

RESULTS

Compared to the matched controls, patients who have MFS displayed elevated rates of surgical complications, including prosthetic instability (1-year, odds ratio (OR) 3.88, 95% confidence interval (CI) [1.58 to 8.66]; 2-year, OR 4.39, 95% CI [2.16 to 8.44]), and revision surgery (2 year, OR 1.79, 95% CI [1.05 to 2.91]). Additionally, patients who have MFS demonstrated significant higher rates of medical complications, including aortic dissection (2.15 versus 0%) and transfusion (OR 2.63, 95% CI [1.31 to 4.90]).

CONCLUSIONS

Patients who have MFS are at higher risks of postoperative complications after TKA, encompassing both medical and surgical complications. Specifically, patients who have MFS have a significantly higher likelihood of experiencing prosthetic instability and requiring revision surgery. Given these results, it is crucial for orthopedic surgeons and patients alike to consider these risks when determining a course of TKA for patients who have MFS.

Targeted next-generation sequencing reveals the genetic mechanism of Chinese Marfan syndrome cohort with ocular manifestation

BACKGROUND

Marfan syndrome (MFS) is a hereditary connective tissue disorder involving multiple systems, including ophthalmologic abnormalities. Most cases are due to heterozygous mutations in the fibrillin-1 gene (FBN1). Other associated genes include LTBP2, MYH11, MYLK, and SLC2A10. There is significant clinical overlap between MFS and other Marfan-like disorders.

PURPOSE

To expand the mutation spectrum of FBN1 gene and validate the pathogenicity of Marfan-related genes in patients with MFS and ocular manifestations.

METHODS

We recruited 318 participants (195 cases, 123 controls), including 59 sporadic cases and 88 families. All patients had comprehensive ophthalmic examinations showing ocular features of MFS and met Ghent criteria. Additionally, 754 cases with other eye diseases were recruited. Panel-based next-generation sequencing (NGS) screened mutations in 792 genes related to inherited eye diseases.

RESULTS

We detected 181 mutations with an 84.7% detection rate in sporadic cases and 87.5% in familial cases. The overall detection rate was 86.4%, with FBN1 accounting for 74.8%. In cases without FBN1 mutations, 23 mutations from seven Marfan-related genes were identified, including four pathogenic or likely pathogenic mutations in LTBP2. The 181 mutations included 165 missenses, 10 splicings, three frameshifts, and three nonsenses. FBN1 accounted for 53.0% of mutations. The most prevalent pathogenic mutation was FBN1 c.4096G>A. Additionally, 94 novel mutations were detected, with 13 de novo mutations in 14 families.

CONCLUSION

We expanded the mutation spectrum of the FBN1 gene and provided evidence for the pathogenicity of other Marfan-related genes. Variants in LTBP2 may contribute to the ocular manifestations in MFS, underscoring its role in phenotypic diversity.

Single-Nucleus Multiomic Analyses Identifies Gene Regulatory Dynamics of Phenotypic Modulation in Human Aneurysmal Aortic Root

Aortic root aneurysm is a potentially life-threatening condition that may lead to aortic rupture and is often associated with genetic syndromes, such as Marfan syndrome (MFS). Although studies with MFS animal models have provided valuable insights into the pathogenesis of aortic root aneurysms, this understanding of the transcriptomic and epigenomic landscape in human aortic root tissue remains incomplete. This knowledge gap has impeded the development of effective targeted therapies. Here, this study performs the first integrative analysis of single-nucleus multiomic (gene expression and chromatin accessibility) and spatial transcriptomic sequencing data of human aortic root tissue under healthy and MFS conditions. Cell-type-specific transcriptomic and cis-regulatory profiles in the human aortic root are identified. Regulatory and spatial dynamics during phenotypic modulation of vascular smooth muscle cells (VSMCs), the cardinal cell type, are delineated. Moreover, candidate key regulators driving the phenotypic modulation of VSMC, such as FOXN3, TEAD1, BACH2, and BACH1, are identified. In vitro experiments demonstrate that FOXN3 functions as a novel key regulator for maintaining the contractile phenotype of human aortic VSMCs through targeting ACTA2. These findings provide novel insights into the regulatory and spatial dynamics during phenotypic modulation in the aneurysmal aortic root of humans.

Acute ischemic stroke with a diagnosis of Marfan syndrome: A report of 3 cases in multifaceted settings

RATIONALE

Marfan syndrome (MFS), which is a dominantly inherited connective tissue disease resulting from a mutation in the FBN1 gene, exhibits variable manifestations affecting the cardiovascular, musculoskeletal, ophthalmologic, and pulmonary systems. Notably, neurologic deficiency, which involves ischemic or hemorrhagic stroke, is a rare but severe manifestation. The safety of rt-PA treatment for ischemic stroke caused by MFS is still under discussion.

PATIENT CONCERNS

In the current report, we discuss 3 atypical MFS cases presented as acute ischemic stroke, compared to those exhibiting cardiovascular and musculoskeletal abnormalities.

DIAGNOSES

Three patients were diagnosed with acute ischemic stroke accompanied by MFS based on clinical manifestations, imaging examinations, and genetic testings.

INTERVENTIONS

The first case underwent intravenous thrombolytic therapy with rt-PA, the second case received antiplatelet therapy, and the third case received anticoagulant therapy and perfusion therapy.

OUTCOMES

The neurologic deficiency of all three patients showed improvement upon discharge, and there were no symptoms of recurrence observed during the follow-up period.

LESSONS SUBSECTIONS

MFS is a rare etiology in young people with embolic stroke of undetermined source. Physicians should take MFS into consideration when they observe the characteristic symptoms during a consultation. The potential pathogenesis of ischemic stroke secondary to MFS may include cardio-embolism, arterial dissection, and hypoperfusion. Although intravenous thrombolysis is a promising therapy to treat acute ischemic stroke, further examinations should be conducted to rule out contraindications in patients with a suspicion of MFS.

Path analysis of illness uncertainty and psychosocial adaptation of patients with Marfan syndrome

AIMS

Marfan syndrome (MFS) is a genetic disorder that causes sudden or chronic cardiovascular problems, which can be fatal. Since MFS patients require regular close medical observation, it is important to understand the factors and pathways associated with psychosocial adaptation to the disease. This study aimed to identify the relationships among illness uncertainty, uncertainty appraisal, and psychosocial adaptation in MFS patients using path analysis.

METHOD AND RESULTS

This descriptive cross-sectional survey study was conducted from October 2020 to March 2021, in compliance with STROBE guidelines. Using data from 179 participants aged older than 18 years, we constructed a hypothetical path model to identify determinants of illness uncertainty, uncertainty appraisal, and psychosocial adaptation. In the path analysis, disease severity, illness uncertainty, anxiety, and social support were significant factors influencing MFS patients' psychosocial adaptation. Disease severity and illness uncertainty exerted direct effects, while anxiety and social support exerted both direct and indirect (through illness uncertainty) effects. Finally, anxiety showed the greatest total effect.

CONCLUSION

These findings are useful for enhancing MFS patients' psychosocial adaptation. Medical professionals should focus on managing disease severity, decreasing anxiety, and increasing social support.

Predicting Marfan Syndrome in Children With Congenital Ectopia Lentis: Development and Validation of a Nomogram

Purpose

To derive an effective nomogram for predicting Marfan syndrome (MFS) in children with congenital ectopia lentis (CEL) using regularly collected data.

Methods

Diagnostic standards (Ghent nosology) and genetic test were applied in all patients with CEL to determine the presence or absence of MFS. Three potential MFS predictors were tested and chosen to build a prediction model using logistic regression. The predictive performance of the nomogram was validated internally through time-dependent receiver operating characteristic curves, calibration curves, and decision curve analysis.

Results

Eyes from 103 patients under 20 years old and with CEL were enrolled in this study. Z score of body mass index (odds ratio [OR] = 0.659; 95% confidence interval [CI], 0.453-0.958), corneal curvature radius (OR = 3.397; 95% CI, 1.829-6.307), and aortic root diameter (OR = 2.342; 95% CI, 1.403-3.911) were identified as predictors of MFS. The combination of the above predictors shows good predictive ability, as indicated by area under the curve of 0.889 (95% CI, 0.826-0.953). The calibration curves showed good agreement between the prediction of the nomogram and the actual observations. In addition, decision curve analysis showed that the nomogram was clinically useful and had better discriminatory power in identifying patients with MFS. For better individual prediction, an online MFS calculator was created.

Conclusions

The nomogram provides accurate and individualized prediction of MFS in children with CEL who cannot be identified with the Ghent criteria, enabling clinicians to personalize treatment plans and improve MFS outcomes.

Translational Relevance

The prediction model may help clinicians identify MFS in its early stages, which could reduce the likelihood of developing severe symptoms and improve MFS outcomes.

miR-632 Induces DNAJB6 Inhibition Stimulating Endothelial-to-Mesenchymal Transition and Fibrosis in Marfan Syndrome Aortopathy

Marfan syndrome (MFS) is a connective tissue disorder caused by FBN1 gene mutations leading to TGF-β signaling hyperactivation, vascular wall weakness, and thoracic aortic aneurysms (TAAs). The pathogenetic mechanisms are not completely understood and patients undergo early vascular surgery to prevent TAA ruptures. We previously reported miR-632 upregulation in MFS TAA tissues compared with non-genetic TAA tissues. DNAJB6 is a gene target of miR-632 in cancer and plays a critical role in blocking epithelial-to-mesenchymal transition by inhibiting the Wnt/β catenin pathway. TGF-β signaling also activates Wnt/β catenin signaling and induces endothelial-to-mesenchymal transition (End-Mt) and fibrosis. We documented that miR-632 upregulation correlated with DNAJB6 expression in both the endothelium and the tunica media of MFS TAA (p < 0.01). Wnt/β catenin signaling, End-Mt, and fibrosis markers were also upregulated in MFS TAA tissues (p < 0.05, p < 0.01 and p < 0.001). Moreover, miR-632 overexpression inhibited DNAJB6, inducing Wnt/β catenin signaling, as well as End-Mt and fibrosis exacerbation (p < 0.05 and p < 0.01). TGF-β1 treatment also determined miR-632 upregulation (p < 0.01 and p < 0.001), with the consequent activation of the aforementioned processes. Our study provides new insights about the pathogenetic mechanisms in MFS aortopathy. Moreover, the high disease specificity of miR-632 and DNAJB6 suggests new potential prognostic factors and/or therapeutic targets in the progression of MFS aortopathy.

Connective tissue disorders and eye: A review and recent updates

Collagen vascular disorders (CVDs), also known as connective tissue diseases (CTDs), are a heterogeneous group of entities that affect the connective tissues and are capable of causing end-organ damage to multiple systems, primarily cardiopulmonary and musculoskeletal. However, the occurrence and severity are highly variable among patients. Ocular involvement occurs in a significant number of these disorders and may precede the onset of other extraocular features, thereby serving as an important marker in the diagnosis of these diseases. A timely and accurate diagnosis enables the management of complications. CTDs are primarily immune-mediated inflammatory diseases; however, classifications have encompassed heritable disorders affecting collagen-containing structures and disorders of vascular development. A review of literature published until 25 January 2022 and collected from various databases using the relevant keywords was conducted. All publications (original articles, review articles, as well as case reports) describing the ocular features in CTDs were studied in detail. The objective of this review is to recognize the common ophthalmic presentations of various autoimmune and heritable CTDs, distinguish them from overlapping diseases, elaborate on the prognosis and management of these varied eye presentations, and deliberate on their impact on other ophthalmic surgeries.

Identification of two variants in PAX3 and FBN1 in a Chinese family with Waardenburg and Marfan syndrome via whole exome sequencing

Both Warrensburg (WS) and Marfan syndrome (MFS) can impair the vision. Here, we recruited a Chinese family consisting of two WS affected individuals (II:1 and III:3) and five MFS affected individuals( I:1, II:2, III:1, III:2, and III:5) as well as one suspected MFS individual (II:4). Using whole exome sequencing (WES) and subsequent PCR-Sanger sequencing, we identified one novel heterozygous variant NM_000438 (PAX3) c.208 T > C, (p.Cys70Arg) from individuals with WS and one previous reported variant NM_000138 (FBN1) c.2740 T > A, (p.Cys914Ser) from individuals with MFS and co-segregated with the diseases. Real-time PCR and Western blot assay showed that, compared to their wild-type, both mRNAs and proteins of  PAX3 and FBN1 mutants reduced in HKE293T cells. Together, our study identified two disease-causing variants in a same Chinese family with WS and MFS, and confirmed their damaged effects on their genes' expression. Therefore, those findings expand the mutation spectrum of PAX3 and provide a new perspective for the potential therapy.

Developmental Foot Deformities in Patients with Connective Tissue Disorders

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Foot deformities make up a large percentage of all orthopaedic complaints in patients with Down syndrome, Marfan syndrome, Ehlers-Danlos syndrome, Larsen syndrome, and osteogenesis imperfecta.

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Some common causes of foot deformities in these conditions include increased ligament laxity, hypotonia, and hypermobility of the joints.

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Treatment options for syndromic foot deformities include the use of foot orthoses, physical therapy, bracing, and various surgical procedures.

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There is limited evidence supporting the use of surgical intervention to correct foot deformities associated with Down syndrome, Marfan syndrome, Ehlers-Danlos syndrome, Larsen syndrome, and osteogenesis imperfecta. Therefore, further research is needed to determine the short-term and long-term outcomes of these procedures.

Novel and recurrent FBN1 mutations causing Marfan syndrome in two Chinese families

Background

To explore the genetic defects of two families with autosomal dominant Marfan syndrome (MFS).

Methods

Two families with MFS were enrolled in this study. The detailed ocular presentations of the patients were recorded. Whole exome sequencing was performed to explore the pathogenic variants and Sanger sequencing was performed to confirm the gene mutations. Segregation analysis among the family members was made and bioinformatics analysis was performed to predict the functional impact of the mutations.

Results

The main ocular presentations of the probands were increased axial length and ectopia lentis. Using whole exome sequencing and Sanger sequencing, a novel heterozygous missense mutation (c.5060G > C, p.Cys1687Ser) and a recurrent missense mutation (c.2168A > T, p.Asp723Val) were identified within FBN1, which were co-segregated with the MFS phenotype in the families. Evolutionary conservation analysis showed that codons 723 and 1,687 were highly conserved among several species. Functional impact predictions made using several online programs suggested that the mutations were pathogenic.

Conclusion

We identified a novel and a recurrent missense mutation in FBN1 in two Chinese families with MFS using whole exome sequencing, and our bioinformatics analysis indicated that the mutations were disease-causing. Our results expand the mutation spectrum of FBN1 and could help us better understand the genetic defects of the patients with MFS.

Femtosecond Laser Combined with Double-Flange Polypropylene Suture Capsular Tension Ring Suspension for the Treatment of Subluxation of Lens in Marfan Syndrome

Purpose

To evaluate the use of femtosecond laser combined with double-flange polypropylene suture capsular tension ring (CTR) suspension to treat subluxation of lens in Marfan syndrome. The objective is to provide safer and more effective surgical procedures for patients. Setting. Eye Hospital, Aier Eye Hospital of Wuhan University, Wuhan, China

Methods

In this retrospective study, we observed sixteen patients (16 eyes) with Marfan syndrome who had undergone this operation. Femtosecond laser incision was performed on the anterior capsule with the lens as the center. The suspending CTR was clipped to anterior capsule to support it, which was secured to the sclera with a double-flange polypropylene suture. Uncorrected visual acuity (UCVA), intraocular pressure (IOP), tilt, and decentration of the intraocular lens (IOL) and postoperative complications were evaluated.

Results

All 16 patients were successfully implanted with suspended CTR and IOL after femtosecond laser assisted surgery. Visual acuity improved significantly after surgery (p < 0.01). At 1 month, 3 months and 6 months postoperatively, the tilt of the IOL was 2.70 ± 0.934, 2.65 ± 0.897, and 2.66 ± 0.781, and the decentration of the IOL was 0.30 ± 0.770, 0.30 ± 0.682, and 0.29 ± 0.737; both had no statistically significant difference between the three groups. After the operation, 4 patients had hyphema and 2 patients experienced a temporary postoperative IOP increase. Only one flange was exposed one month after operation and recovered right after secondary adjustment.

Conclusion

Femtosecond laser combined with double-flange polypropylene suture CTR suspension was effective in fixing the lens capsule to the scleral wall in cases of subluxation of lens seen in Marfan syndrome during our short-term observation. The long-term efficacy of this operation needs further observation and follow-up.

[Latest advances in the diagnosis and treatment of Marfan syndrome]

Marfan syndrome (MFS) is a multisystem connective tissue disease with autosomal dominant inheritance. It is mainly caused by FBN1 gene mutation and often has different clinical manifestations. Neonatal MFS is especially rare with severe conditions and a poor prognosis. At present, there is still no radical treatment method for MFS, but early identification, early diagnosis, and early treatment can effectively prolong the life span of patients. This article reviews the latest advances in the diagnosis and treatment of MFS.

Treatment of long-term endophthalmitis developing after intraocular lens implantation in children: a retrospective study

Background

To discussed the risk factor and the management of vitrectomy for long-term endophthalmitis developing after intraocular lens (IOL) implantation in children.

Methods

We retrospectively investigated the clinical characteristics and surgical outcomes of long-term endophthalmitis developing after IOL implantation in children.

Results

Four eyes of four children were included in the study. The mean time to endophthalmitis development after IOL implantation was 3.0 ± 0.8 years. The corneal or scleral sutures may have been caused the infection. All 4 patients underwent vitrectomy and received intravitreal antibiotics with or without IOL removal. At the last follow-up, the outcomes were satisfactory; the fundus was clear, the retina remained attached, the visual acuity improved, and there were no severe complications.

Conclusions

The use of scleral sutures and the exposure of conceal sutures may induce the onset of long-term endophthalmitis after IOL implantation. Complete vitrectomy and appropriate use of antibiotics are effective in the treatment of long-term endophthalmitis developing after IOL implantation in children.

Identification of Novel FBN2 Variants in a Cohort of Congenital Contractural Arachnodactyly

Congenital contractural arachnodactyly (CCA) is a rare autosomal dominant disorder of connective tissue characterized by crumpled ears, arachnodactyly, camptodactyly, large joint contracture, and kyphoscoliosis. The nature course of CCA has not been well-described. We aim to decipher the genetic and phenotypic spectrum of CCA. The cohort was enrolled in Beijing Jishuitan Hospital and Peking Union Medical College Hospital, Beijing, China, based on Deciphering disorders Involving Scoliosis and COmorbidities (DISCO) study (http://www.discostudy.org/). Exome sequencing was performed on patients’ blood DNA. A recent published CCA scoring system was validated in our cohort. Seven novel variants and three previously reported FBN2 variants were identified through exome sequencing. Two variants outside of the neonatal region of FBN2 gene were found. The phenotypes were comparable between patients in our cohort and previous literature, with arachnodactyly, camptodactyly and large joints contractures found in almost all patients. All patients eligible for analysis were successfully classified into likely CCA based on the CCA scoring system. Furthermore, we found a double disease-causing heterozygous variant of FBN2 and ANKRD11 in a patient with blended phenotypes consisting of CCA and KBG syndrome. The identification of seven novel variants broadens the mutational and phenotypic spectrum of CCA and may provide implications for genetic counseling and clinical management.

Into the Tissues: Extracellular Matrix and Its Artificial Substitutes: Cell Signalling Mechanisms

The existence of orderly structures, such as tissues and organs is made possible by cell adhesion, i.e., the process by which cells attach to neighbouring cells and a supporting substance in the form of the extracellular matrix. The extracellular matrix is a three-dimensional structure composed of collagens, elastin, and various proteoglycans and glycoproteins. It is a storehouse for multiple signalling factors. Cells are informed of their correct connection to the matrix via receptors. Tissue disruption often prevents the natural reconstitution of the matrix. The use of appropriate implants is then required. This review is a compilation of crucial information on the structural and functional features of the extracellular matrix and the complex mechanisms of cell–cell connectivity. The possibilities of regenerating damaged tissues using an artificial matrix substitute are described, detailing the host response to the implant. An important issue is the surface properties of such an implant and the possibilities of their modification.

Musculoskeletal diseases in Marfan syndrome: a nationwide registry study

Background

Marfan syndrome is associated with abnormalities in the musculoskeletal system including scoliosis, pectus deformities, protrusio acetabuli, and foot deformities. Over a life span, many patients with Marfan syndrome will need treatment; however, the musculoskeletal morbidity over a life span is not well described. The aim of the present study was to assess the overall burden of musculoskeletal disease in patients with Marfan syndrome.

Materials and methods

A registry-based, nationwide epidemiological study of patients with a Ghent II verified Marfan syndrome diagnosis from 1977 to 2014. Each patient was matched on age, and sex with up to 100 controls from the background population.

Results

We identified 407 patients with Marfan syndrome and 40,700 controls and compared their musculoskeletal diagnoses and surgical treatments using Cox proportional hazards ratio (HR). The risk of a registration of a musculoskeletal diagnosis in patients with Marfan syndrome was significantly increased compared to controls (HR: 1.94 (1.69–2.24). One out of six with Marfan syndrome was registered with scoliosis (HR: 36.7 (27.5–48.9). Scoliosis was more common in women with Marfan syndrome compared to men (HR: 4.30 (1.73–1.08)). One out of 11 were registered with a pectus deformity HR: 40.8 (28.1–59.3), and one out of six with a deformity of the foot. Primarily pes planus (HR: 26.0 (15.2–44.3). The proportion of patients with Marfan syndrome (94/407) that underwent musculoskeletal surgery was also significantly higher (HR: 1.76 (1.43–2.16)). The major areas of surgery were the spine, pectups correction, and surgery of the foot/ankle. Ten patients with Marfan syndrome had elective orthopedic surgery without being recognized and diagnosed with Marfan syndrome until later in life. None of these had scoliosis, pectus deformity or a foot deformity. Among patients with an aortic dissection, the age at dissection was 34.3 years in those with at least one major musculoskeletal abnormality. In patients without a major abnormality the age at dissection was 45.1 years (p < 0.01).

Conclusions

The extent of musculoskeletal disease is quite significant in Marfan syndrome, and many will need corrective surgery during their life span. Surgeons should be aware of undiagnosed patients with Marfan syndrome when treating patients with a Marfan syndrome like-phenotype.

Connective Tissue Disease Patients Maintain Greater Distraction During Growth Friendly Surgery

STUDY DESIGN

Multicenter retrospective study.

BACKGROUND

Recent studies have demonstrated diminishing returns in patients with early onset scoliosis (EOS) undergoing repeated lengthening of growing rods. Little is known about whether this same phenomenon occurs in patients with lax connective tissue disease (CTD). The primary purpose of this study is to investigate whether EOS patients with connective tissue laxity disorders have diminishing returns during growth friendly surgery.

METHODS

CTD EOS patients below 10 years old, underwent growth friendly spine surgery with distal anchors and at least 1 proximal spine anchor, and had minimum follow-up of 5 years were included in this study. Coronal T1-S1 height at preindex surgery, postindex, and every available lengthening was assessed. Mean coronal height change during early set distractions and late set distractions were calculated for the cohort. To account for varying distraction intervals, we normalized the distractions by the time interval. The outcome parameter was T1-S1 height gain, mm/year.

RESULTS

Twenty-one CTD patients were included in this study. Total coronal height (T1-S1) was 26.7MHCcm before index, 32.2 cm at D1-D3, 34.7 cm at D4-D6, and 36.7 cm at D7-L10. There were no significant differences in coronal height gains between early and late distractions (P=0.70). Moreover, when normalized for time, there was no significant difference in net gain per year at different lengthening time points for the CTD group, P=0.59.

CONCLUSION

There is no evidence of diminishing returns in coronal T1-S1 height gain in patients with EOS in the setting of CTD.

LEVEL OF EVIDENCE

Level III.

Pediatrics for Disability: A Comprehensive Approach to Children with Syndromic Psychomotor Delay

Intellectual disability is the impairment of cognitive, linguistic, motor and social skills that occurs in the pediatric age and is also described by the term "mental retardation". Intellectual disability occurs in 3-28 % of the general population due to a genetic cause, including chromosome aberrations. Among people with intellectual disabilities, the cause of the disability was identified as a single gene disorder in up to 12 %, multifactorial disorders in up to 4 %, and genetic disorders in up to 8.5 %. Children affected by a malformation syndrome associated with mental retardation or intellectual disability represent a care challenge for the pediatrician. A multidisciplinary team is essential to manage the patient, thereby controlling the complications of the syndrome and promoting the correct psychophysical development. This requires continuous follow-up of these children by the pediatrician, which is essential for both the clinical management of the syndrome and facilitating the social integration of these children.

Ischemic Stroke Genetics: What Is New and How to Apply It in Clinical Practice?

The etiology of ischemic stroke is multifactorial. Although receiving less emphasis, genetic causes make a significant contribution to ischemic stroke genesis, especially in early-onset stroke. Several stroke classification systems based on genetic information corresponding to various stroke phenotypes were proposed. Twin and family history studies, as well as candidate gene approach, are common methods to discover genetic causes of stroke, however, both have their own limitations. Genome-wide association studies and next generation sequencing are more efficient, promising and increasingly used for daily diagnostics. Some monogenic disorders, despite covering only about 7% of stroke etiology, may cause well-known clinical manifestations that include stroke. Polygenic disorders are more frequent, causing about 38% of all ischemic strokes, and their identification is a rapidly developing field of modern stroke genetics. Current advances in human genetics provide opportunity for personalized prevention of stroke and novel treatment possibilities. Genetic risk scores (GRS) and extended polygenic risk scores (PRS) estimate cumulative contribution of known genetic factors to a specific outcome of stroke. Combining those scores with clinical information and risk factor profiles might result in better primary stroke prevention. Some authors encourage the use of stroke gene panels for stroke risk evaluation and further stroke research. Moreover, new biomarkers for stroke genetic causes and novel targets for gene therapy are on the horizon. In this article, we summarize the latest evidence and perspectives of ischemic stroke genetics that could be of interest to the practitioner and useful for day-to-day clinical work.

Genome-wide methylation patterns in Marfan syndrome

Background

Marfan syndrome (MFS) is a connective tissue disorder caused by mutations in the Fibrillin-1 gene (FBN1). Here, we undertook the first epigenome-wide association study (EWAS) in patients with MFS aiming at identifying DNA methylation loci associated with MFS phenotypes that may shed light on the disease process.

Methods

The Illumina 450 k DNA-methylation array was used on stored peripheral whole-blood samples of 190 patients with MFS originally included in the COMPARE trial. An unbiased genome-wide approach was used, and methylation of CpG-sites across the entire genome was evaluated. Additionally, we investigated CpG-sites across the FBN1-locus (15q21.1) more closely, since this is the gene defective in MFS. Differentially Methylated Positions (DMPs) and Differentially Methylated Regions (DMRs) were identified through regression analysis. Associations between methylation levels and aortic diameters and presence or absence of 21 clinical features of MFS at baseline were analyzed. Moreover, associations between aortic diameter change, and the occurrence of clinical events (death any cause, type-A or -B dissection/rupture, or aortic surgery) and methylation levels were analyzed.

Results

We identified 28 DMPs that are significantly associated with aortic diameters in patients with MFS. Seven of these DMPs (25%) could be allocated to a gene that was previously associated with cardiovascular diseases (HDAC4, IGF2BP3, CASZ1, SDK1, PCDHGA1, DIO3, PTPRN2). Moreover, we identified seven DMPs that were significantly associated with aortic diameter change and five DMP’s that associated with clinical events. No significant associations at p < 10^–8 or p < 10^–6 were found with any of the non-cardiovascular phenotypic MFS features. Investigating DMRs, clusters were seen mostly on X- and Y, and chromosome 18–22. The remaining DMRs indicated involvement of a large family of protocadherins on chromosome 5, which were not reported in MFS before.

Conclusion

This EWAS in patients with MFS has identified a number of methylation loci significantly associated with aortic diameters, aortic dilatation rate and aortic events. Our findings add to the slowly growing literature on the regulation of gene expression in MFS patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01204-4.

Construction and Evaluation of Recombinant Chimeric Fibrillin and Elastin Fragment in Human Mesenchymal Stem Cells

BACKGROUND

Diverse extracellular matrix (ECM) proteins physically interact with stem cells and regulate stem cell function. However, the large molecular weight of the natural ECM renders large-scale fabrication of a similar functional structure challenging.

OBJECTIVE

The objective of this study was to construct a low molecular weight and multifunctional chimeric form of recombinant ECM to stimulate mesenchymal stem cell (MSC) for tissue repair. We engineered Fibrillin-1PF14 fused to an elastin-like polypeptide to develop a new biomimetic ECM for stem cell differentiation and investigated whether this recombinant chimeric Fibrillin-Elastin fragment (rcFE) was effective on human nasal inferior turbinate-derived mesenchymal stem cells (hTMSCs).

METHODS

hTMSCs were grown in the medium supplemented with rcFE, then the effect of the protein was confirmed through cell adhesion assay, proliferation assay, and real-time PCR.

RESULTS

rcFE enhanced the adhesion activity of hTMSCs by 2.7-fold at the optimal concentration, and the proliferation activity was 2.6-fold higher than that of the control group (non-treatment rcFE). In addition, when smooth muscle cell differentiation markers were identified by real-time PCR, Calponin increased about 6-fold, α-actin about 9-fold, and MYH11 about 10-fold compared to the control group.

CONCLUSION

Chimeric rcFE enhanced cellular functions such as cell adhesion, proliferation, and smooth muscle differentiation of hTMSCs, suggesting that the rcFE can facilitate the induction of tissue regeneration.

Hyperkyphosis is not dependent on bone mass and quality in the mouse model of Marfan syndrome

Marfan syndrome (MFS) is an autosomal dominant disease affecting cardiovascular, ocular and skeletal systems. It is caused by mutations in the fibrillin-1 (FBN1) gene, leading to structural defects of connective tissue and increased activation of TGF-β. Angiotensin II (ang-II) is involved in TGF-β activity and in bone mass regulation. Inhibition of TGF-β signaling by blockage of the ang-II receptor 1 (AT1R) via losartan administration leads to improvement of cardiovascular and pulmonary phenotypes, but has no effect on skeletal phenotype in the haploinsufficient mouse model of MFS mg^R, suggesting a distinct mechanism of pathogenesis in the skeletal system. Here we characterized the skeletal phenotypes of the dominant-negative model for MFS mgΔ^lpn and tested the effect of inhibition of ang-II signaling in improving those phenotypes. As previously shown, heterozygous mice present hyperkyphosis, however we now show that only males also present osteopenia. Inhibition of ang-II production by ramipril minimized the kyphotic deformity, but had no effect on bone microstructure in male mutant animals. Histological analysis revealed increased thickness of the anterior longitudinal ligament (ALL) of the spine in mutant animals (25.8 ± 6.3 vs. 29.7 ± 7.7 μm), coupled with a reduction in type I (164.1 ± 8.7 vs. 139.0 ± 4.4) and increase in type III (86.5 ± 10.2 vs. 140.4 ± 5.6) collagen in the extracellular matrix of this ligament. In addition, we identified in the MFS mice alterations in the erector spinae muscles which presented thinner muscle fibers (1035.0 ± 420.6 vs. 655.6 ± 239.5 μm²) surrounded by increased area of connective tissue (58.17 ± 6.52 vs. 105.0 ± 44.54 μm²). Interestingly, these phenotypes were ameliorated by ramipril treatment. Our results reveal a sex-dependency of bone phenotype in MFS, where females do not present alterations in bone microstructure. More importantly, they indicate that hyperkyphosis is not a result of osteopenia in the MFS mouse model, and suggest that incompetent spine ligaments and muscles are responsible for the development of that phenotype.

Dermatologic manifestations of pediatric cardiovascular diseases: Skin as a reflection of the heart

Cutaneous disease can often be an initial clue of an underlying cardiovascular disease. Many congenital conditions (ie, Noonan syndrome with multiple lentigines, Carney complex, and Fabry disease) and acquired conditions may present initially with specific cutaneous features that should prompt clinicians to conduct a full cardiac workup. Given the extensive number of conditions with both cardiovascular and cutaneous findings, this review will focus on diseases with cardiocutaneous pathology with hopes of raising clinician awareness of these associations to decrease morbidity and mortality, as several of these diseases often result in fatal outcomes.

Compound heterozygous mutations in the LTBP2 gene associated with microspherophakia in a Chinese patient: a case report and literature review

BACKGROUND

Microspherophakia (MSP, OMIM 251,750) is a rare inherited autosomal recessive eye disorder characterized by small spherically shaped lens. Several studies have indicated that the transforming growth factor-beta (TGF-beta) binding proteins(LTBP2) gene mutation is the predominant cause of MSP. In our study, novel compound heterozygous mutations in the LTBP2 gene associated with MSP were reported, which was different from previous reported homozygous mutations.

CASE PRESENTATION

The proband was an 18-year-old male in Western China with bilateral MSP, accompanied by ectopia lentis, secondary glaucoma and blindness in both eyes. In our hospital, he received bilateral lens resection and trabeculectomy combined with peripheral iridotomy. Using next-generation sequencing (NGS)-based gene panel tests, we identified pathogenic mutations in the peripheral blood DNA sample from the proband: c.3614_3618dupCTGGC (exon24, NM_000428) and c.2819G > A (exon18, NM_000428). The presence of the novel compound heterozygous mutations in the LTBP2 gene was linked with the development of MSP. Sanger sequencing confirmed the existence of one of the two variants in each parent respectively.

CONCLUSION

Our results demonstrated a rare case of MSP phenotype associated with novel compound heterozygous mutations in the LTBP2 gene using NGS technology.

Controversy and Consideration of Refractive Surgery in Patients with Heritable Disorders of Connective Tissue

Heritable Disorders of Connective Tissue (HDCTs) are syndromes that disrupt connective tissue integrity. They include Osteogenesis Imperfecta (OI), Ehlers Danlos Syndrome (EDS), Marfan Syndrome (MFS), Loeys-Dietz Syndrome (LDS), Epidermolysis Bullosa (EB), Stickler Syndrome (STL), Wagner Syndrome, and Pseudoxanthoma Elasticum (PXE). Because many patients with HDCTs have ocular symptoms, commonly myopia, they will often present to the clinic seeking refractive surgery. Currently, corrective measures are limited, as the FDA contraindicates laser-assisted in-situ keratomileusis (LASIK) in EDS and discourages the procedure in OI and MFS due to a theoretically increased risk of post-LASIK ectasia, poor wound healing, poor refractive predictability, underlying keratoconus, and globe rupture. While these disorders present with a wide range of ocular manifestations that are associated with an increased risk of post-LASIK complications (e.g., thinned corneas, ocular fragility, keratoconus, glaucoma, ectopia lentis, retinal detachment, angioid streaks, and ocular surface disease), their occurrence and severity are highly variable among patients. Therefore, an HDCT diagnosis should not warrant an immediate disqualification for refractive surgery. Patients with minimal ocular manifestations can consider LASIK. In contrast, those with preoperative signs of corneal thinning and ocular fragility may find the combination of collagen cross-linking (CXL) with either photorefractive keratotomy (PRK), small incision lenticule extraction (SMILE) or a phakic intraocular lens (pIOL) implant to be more suitable options. However, evidence of refractive surgery performed on patients with HDCTs is limited, and surgeons must fully inform patients of the unknown risks and complications before proceeding. This paper serves as a guideline for future studies to evaluate refractive surgery outcomes in patients with HDCTs.

Evaluation of axial length/total corneal refractive power ratio as a potential marker for ocular diagnosis of Marfan's syndrome in children

AIM

To investigate whether the axial length (AL)/total corneal refractive power (TCRP) ratio is a sensitive and simple factor that can be used for the early diagnosis of Marfan's syndrome (MFS) in children.

METHODS

The relationship between the AL/TCRP ratio and the diagnosis of MFS for 192 eyes in 97 children were evaluate. The biological characteristics, including age, sex, AL, and TCRP, were collected from medical records. Receiver operating characteristic (ROC) curve analysis was performed to investigate whether the AL/TCRP ratio effectively distinguishes MFS from other subjects. The Youden index was used to re-divide the whole population into two groups according to an AL/TCRP ratio of 0.59.

RESULTS

Of 96 subjects (mean age 7.46±3.28y) evaluated, 56 (110 eyes) had a definite diagnosis of MFS in childhood based on the revised Ghent criteria, 41 (82 eyes) with diagnosis of congenital ectopia lentis (EL) were included as a control group. AL was negatively correlated with TCRP, with a linear regression coefficient of -0.36 (R ²=0.08). A significant correlation was found between age and the AL/TCRP ratio (P=0.023). ROC curve analysis showed that the AL/TCRP ratio distinguished MFS from the other patients at a threshold of 0.59. MFS patients were present in 24/58 (41.38%) patients with an AL/TCRP ratio of ≤0.59 and in 34/39 (87.18%) patients with an AL/TCRP ratio of >0.59.

CONCLUSION

An AL/TCRP ratio of >0.59 is significantly associated with the risk of MFS. The AL/TCRP ratio should be measured as a promising marker for the prognosis of children MFS. Changes in the AL/TCRP ratio should be monitored over time.

CRISPR/Cas9 in zebrafish: An attractive model for FBN1 genetic defects in humans

Background

Mutations in the fibrillin‐1 gene (FBN1) are associated with various heritable connective tissue disorders (HCTD). The most studied HCTD is Marfan syndrome. Ninety percent of Marfan syndrome is caused by mutations in the FBN1 gene. The zebrafish share high genetic similarity to humans, representing an ideal model for genetic research of human diseases. This study aimed to generate and characterize fbn1^+/− mutant zebrafish using the CRISPR/Cas9 gene‐editing technology.

Methods

CRISPR/Cas9 was applied to generate an fbn1 frameshift mutation (fbn1^+/−) in zebrafish. F1 fbn1^+/− heterozygotes were crossed with transgenic fluorescent zebrafish to obtain F2 fbn1^+/− zebrafish. Morphological abnormalities were assessed in F2 fbn1^+/− zebrafish by comparing with the Tuebingen (TU) wild‐type controls at different development stages.

Results

We successfully generated a transgenic line of fbn1^+/− zebrafish. Compared with TU wild‐type zebrafish, F2 fbn1^+/− zebrafish exhibited noticeably decreased pigmentation, increased lengths, slender body shape, and abnormal cardiac blood flow from atrium to ventricle.

Conclusion

We generated the first fbn1^+/− zebrafish model using CRISPR/Cas9 gene‐editing approach to mimic FBN1 genetic defects in humans, providing an attractive model of Marfan syndrome and a method to determine the pathogenicity of gene mutation sites.

Orthopaedic Conditions Associated with Aneurysms

Orthopaedic surgeons are sometimes the first specialists encountered by patients with inherited conditions that predispose them to aneurysms. The skeletal features are evident, but the aneurysm is silent. Early recognition of the conditions associated with aneurysms can lead to effective treatment and minimize risks of morbidity and death. Marfan syndrome is characterized by abnormal fibrillin-1 protein and has a broad range of skeletal manifestations, including scoliosis, hindfoot deformity, arachnodactyly, pectus excavatum or carinatum deformity, dural ectasia, and acetabular protrusio. Aneurysm-associated complications are the leading cause of early morbidity and death in patients with Marfan syndrome. Ehlers-Danlos syndrome is caused by a disturbance in collagen biosynthesis most commonly resulting in joint hypermobility and skin abnormalities. Among the types of Ehlers-Danlos syndrome, vascular Ehlers-Danlos syndrome presents the highest risk of vascular complications. Clubfoot and joint dislocations are common presenting symptoms in vascular Ehlers-Danlos syndrome. Loeys-Dietz syndrome is a connective tissue disorder resulting in aortic root dilation and several skeletal manifestations, including scoliosis, cervical malformations, joint contractures, and foot deformities.

A Tale of Two Organ Systems: Imaging Review of Diseases Affecting the Thoracic and Neurological Systems. Part 2

In an era of rapidly expanding knowledge and sub-specialization, it is becoming increasingly common to focus on one organ system. However, the human body is intimately linked, and disease processes affecting one region of the body not uncommonly affect the other organ systems as well. Understanding diseases from a macroscopic perspective, rather than a narrow vantage point, enables efficient and accurate diagnosis. This tenet holds true for diseases affecting both the thoracic and neurologic systems; in isolation, the radiologic appearance of disease in one organ system may be nonspecific, but viewing the pathophysiologic process in both organ systems may markedly narrow the differential considerations, and potentially lead to a definitive diagnosis. In this article, we discuss a variety of disease entities known to affect both the thoracic and neurological systems, either manifesting simultaneously or at different periods of time. Some of these conditions may show neither thoracic nor neurological manifestations. These diseases have been systematically classified into infectious, immune-mediated/ inflammatory, vascular, syndromic/ hereditary and neoplastic disorders. The underlying pathophysiological mechanisms linking both regions and radiologic appearances in both organ systems are discussed. When appropriate, brief clinical and diagnostic information is provided. Ultimately, accurate diagnosis will lead to expedited triage and prompt institution of potentially life-saving treatment for these groups of complex disorders.

Clinical Ocular Diagnostic Model of Marfan Syndrome in Patients With Congenital Ectopia Lentis by Pentacam AXL System

Purpose

To construct an ocular diagnostic model of Marfan syndrome (MFS) distinguishing MFS from congenital ectopia lentis by the Pentacam AXL system.

Methods

Multivariable logistic regression was performed for the MFS ocular model. Furthermore, discrimination and calibration were validated externally. Data for 96 patients with ectopia lentis were assigned to the training cohort. Eighty patients with ectopia lentis were assigned to the test cohort. Diagnosis of MFS was based on the Ghent-2 criteria and diagnosis of congenital ectopia lentis in the control did not comply with the Ghent-2 criteria.

Results

The clinical model was based on the axial length/total corneal refractive power ratio. In the training cohort, the area under the receiver operating characteristic curve was 0.816 (95% confidence interval, 0.754-0.878) in the final model, which showed better performance than the previous minor criteria for diagnosis MFS of myopia of more than 3 diopters. In the test cohort, the area under the receiver operating characteristic curve was 0.818 (95% confidence interval, 0.718-0.918). In decision curve analysis, the net benefit of the model was better between threshold probabilities of 40% to 80%.

Conclusions

We demonstrated the value of the axial length/total corneal refractive power ratio as a potential diagnostic marker of MFS and clinical performance of diagnostic models, which may assist ophthalmologists in rapid identification of the patients at high risk of MFS.

Translational Relevance

This clinical ocular diagnostic model can be easily applied using the Pentacam AXL system. This model aids in the early differential diagnosis of MFS from other forms of congenital ectopia lentis, which may decrease the risk of developing severe ocular symptoms.

2020 APHRS/HRS expert consensus statement on the investigation of decedents with sudden unexplained death and patients with sudden cardiac arrest, and of their families

This international multidisciplinary document intends to provide clinicians with evidence-based practical patient-centered recommendations for evaluating patients and decedents with (aborted) sudden cardiac arrest and their families. The document includes a framework for the investigation of the family allowing steps to be taken, should an inherited condition be found, to minimize further events in affected relatives. Integral to the process is counseling of the patients and families, not only because of the emotionally charged subject, but because finding (or not finding) the cause of the arrest may influence management of family members. The formation of multidisciplinary teams is essential to provide a complete service to the patients and their families, and the varied expertise of the writing committee was formulated to reflect this need. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by Class of Recommendation and Level of Evidence. The recommendations were opened for public comment and reviewed by the relevant scientific and clinical document committees of the Asia Pacific Heart Rhythm Society (APHRS) and the Heart Rhythm Society (HRS); the document underwent external review and endorsement by the partner and collaborating societies. While the recommendations are for optimal care, it is recognized that not all resources will be available to all clinicians. Nevertheless, this document articulates the evaluation that the clinician should aspire to provide for patients with sudden cardiac arrest, decedents with sudden unexplained death, and their families.

Acute Type A Dissection during Pregnancy with Marfan's Syndrome

Background  Marfan's syndrome (MFS) is a connective tissue disorder, caused by a mutation in the FBN-1 gene and affecting multiple organ systems including the vascular system. During pregnancy, women with MFS have an increased risk of aortic dissection due to changes in the cardiovascular system.

Case Description  We present a 39-year-old woman that suffered from an acute aortic dissection in week 33 of her third pregnancy who urgently required lifesaving surgery. Three-dimensional reconstruction of computed tomography scan was performed with unborn child in utero.

Conclusion  Monitoring of patients with suspected or confirmed MFS appears essential and interdisciplinary treatment and prevention strategies are required.

Systemic diseases and the cornea

There is a number of systemic diseases affecting the cornea. These include endocrine disorders (diabetes, Graves' disease, Addison's disease, hyperparathyroidism), infections with viruses (SARS-CoV-2, herpes simplex, varicella zoster, HTLV-1, Epstein-Barr virus) and bacteria (tuberculosis, syphilis and Pseudomonas aeruginosa), autoimmune and inflammatory diseases (rheumatoid arthritis, Sjögren's syndrome, lupus erythematosus, gout, atopic and vernal keratoconjunctivitis, multiple sclerosis, granulomatosis with polyangiitis, sarcoidosis, Cogan's syndrome, immunobullous diseases), corneal deposit disorders (Wilson's disease, cystinosis, Fabry disease, Meretoja's syndrome, mucopolysaccharidosis, hyperlipoproteinemia), and genetic disorders (aniridia, Ehlers-Danlos syndromes, Marfan syndrome). Corneal manifestations often provide an insight to underlying systemic diseases and can act as the first indicator of an undiagnosed systemic condition. Routine eye exams can bring attention to potentially life-threatening illnesses. In this review, we provide a fairly detailed overview of the pathologic changes in the cornea described in various systemic diseases and also discuss underlying molecular mechanisms, as well as current and emerging treatments.

Visual outcomes of lens subluxation surgery with Cionni modified capsular tension rings in Marfan syndrome

Marfan syndrome (MFS) is a hereditary disease with an incidence of 0.3% in the general population. Approximately 60% of MFS patients with FBN1 gene mutation will suffer ectopia lentis (EL) from the age of 3. With the development of EL, severe loss of vision will accrue because of lens tilt and glaucoma. Cionni modified capsular tension rings (MCTR) has been applied in the surgery for EL in MFS patients. To evaluate visual acuity and safety of using MCTR during lens subluxation surgery in MFS patients, 66 MFS patients (110 eyes) were included in our study, with the mean duration of follow-up of 4.7 months (SD 1.76 months). The capsular bags were preserved in 101 eyes (91.81%) with MCTR implantation. There was an overall significant improvement in BCVA at 1-month follow-up which was maintained at 3 months. Multivariable linear regression revealed that older age at first visit was associated with greater postoperative BCVA at the 1-month follow-up (P = 0.007). A significant difference was found between different degrees of lens subluxation and the length of surgical time and complications. At follow-up, only two eyes (1.98%) were identified to have developed retinal detachments. In conclusion, better visual outcomes can be achieved when patients received an early operation with MCTR implantation.

The mgΔlpn mouse model for Marfan syndrome recapitulates the ocular phenotypes of the disease

PURPOSE

Fibrillin-1 and -2 are major components of tissue microfibrils that compose the ciliary zonule and cornea. While mutations in human fibrillin-1 lead to ectopia lentis, a major manifestation of Marfan syndrome (MFS), in mice fibrillin-2 can compensate for reduced/lack of fibrillin-1 and maintain the integrity of ocular structures. Here we examine the consequences of a heterozygous dominant-negative mutation in the Fbn1 gene in the ocular system of the mgΔ^lpn mouse model for MFS.

METHODS

Eyes from mgΔ^lpn and wild-type mice at 3 and 6 months of age were analyzed by histology. The ciliary zonule was analyzed by scanning electron microscopy (SEM) and immunofluorescence.

RESULTS

Mutant mice presented a significantly larger distance of the ciliary body to the lens at 3 and 6 months of age when compared to wild-type, and ectopia lentis. Immunofluorescence and SEM corroborated those findings in MFS mice, revealing a disorganized mesh of microfibrils on the floor of the ciliary body. Moreover, mutant mice also had a larger volume of the anterior chamber, possibly due to excess aqueous humor. Finally, losartan treatment had limited efficacy in improving ocular phenotypes.

CONCLUSIONS

In contrast with null or hypomorphic mutations, expression of a dominant-negative form of fibrillin-1 leads to disruption of microfibrils in the zonule of mice. This in turn causes lens dislocation and enlargement of the anterior chamber. Therefore, heterozygous mgΔ^lpn mice recapitulate the major ocular phenotypes of MFS and can be instrumental in understanding the development of the disease.

The Molecular Genetics of Marfan Syndrome

Marfan syndrome (MFS) is a complex connective tissue disease that is primarily characterized by cardiovascular, ocular and skeletal systems disorders. Despite its rarity, MFS severely impacts the quality of life of the patients. It has been shown that molecular genetic factors serve critical roles in the pathogenesis of MFS. FBN1 is associated with MFS and the other genes such as FBN2, transforming growth factor beta (TGF-β) receptors (TGFBR1 and TGFBR2), latent TGF-β-binding protein 2 (LTBP2) and SKI, amongst others also have their associated syndromes, however high overlap may exist between these syndromes and MFS. Abnormalities in the TGF-β signaling pathway also contribute to the development of aneurysms in patients with MFS, although the detailed molecular mechanism remains unclear. Mutant FBN1 protein may cause unstableness in elastic structures, thereby perturbing the TGF-β signaling pathway, which regulates several processes in cells. Additionally, DNA methylation of FBN1 and histone acetylation in an MFS mouse model demonstrated that epigenetic factors play a regulatory role in MFS. The purpose of the present review is to provide an up-to-date understanding of MFS-related genes and relevant assessment technologies, with the aim of laying a foundation for the early diagnosis, consultation and treatment of MFS.

2020 APHRS/HRS expert consensus statement on the investigation of decedents with sudden unexplained death and patients with sudden cardiac arrest, and of their families

This international multidisciplinary document intends to provide clinicians with evidence-based practical patient-centered recommendations for evaluating patients and decedents with (aborted) sudden cardiac arrest and their families. The document includes a framework for the investigation of the family allowing steps to be taken, should an inherited condition be found, to minimize further events in affected relatives. Integral to the process is counseling of the patients and families, not only because of the emotionally charged subject, but because finding (or not finding) the cause of the arrest may influence management of family members. The formation of multidisciplinary teams is essential to provide a complete service to the patients and their families, and the varied expertise of the writing committee was formulated to reflect this need. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by Class of Recommendation and Level of Evidence. The recommendations were opened for public comment and reviewed by the relevant scientific and clinical document committees of the Asia Pacific Heart Rhythm Society (APHRS) and the Heart Rhythm Society (HRS); the document underwent external review and endorsement by the partner and collaborating societies. While the recommendations are for optimal care, it is recognized that not all resources will be available to all clinicians. Nevertheless, this document articulates the evaluation that the clinician should aspire to provide for patients with sudden cardiac arrest, decedents with sudden unexplained death, and their families.

The pattern and progression of hearing loss in Marfan Syndrome: A study of children and young adults

OBJECTIVE

(s): To describe the prevalence, type, severity, and progression of hearing loss (HL) in children and young adults with Marfan Syndrome (MFS), and to evaluate the influence of comorbidities on HL.

STUDY DESIGN

Retrospective database analysis.

RESULTS

Of 70 patients with MFS, 52.8% (N = 37) had HL. Within the HL group, 75.7% (N = 28) had bilateral HL, while 24.3% (N = 9) had unilateral HL. 21.4% (N = 15) had moderate or more severe HL. The overall prevalence of CHL was 40.5% (N = 15), SNHL 13.5% (N = 5), and mixed HL 37.8% (N = 14). The mean initial age of HL was 8.4 years (range 0.8-24.0). HL was more prevalent in patients with MFS who also experienced chronic otitis media (ES 1.00, 95% CI, 0.32-1.68) and skull anomalies (ES 0.75, 95% CI, 0.07-1.44) as well as for patients with hypertension (ES 2.17, 95% CI, -1.29-5.64).

CONCLUSIONS

Children and young adults with Marfan syndrome have a high likelihood of hearing loss, with high rates of CHL, chronic otitis media, and Eustachian tube dysfunction. SNHL is also prevalent in this syndrome; hypertension increased the likelihood of SNHL. Early audiologic screening is needed to ascertain type of HL and to efficiently direct patient care in this population.

Echocardiographic study in children with osteogenesis imperfecta

BACKGROUND

Osteogenesis imperfecta is a collagen type I bone disorder. Recently, extra-skeletal manifestations have been described, including many cardiovascular alterations. This study aims to report echocardiogram study in children with osteogenesis imperfecta compared to a control group.

METHODS

A cross-sectional comparative study took place in the Reference Center for Treatment of Osteogenesis Imperfecta in Southern Brazil. Fifty-four patients with osteogenesis imperfecta were paired with 54 controls, based on body surface area, and echocardiogram findings were compared.

RESULTS

All cases were asymptomatic for cardiac manifestations. The case group presented significant larger values in aortic diameter, left atrium diameter, left ventricule end-diastolic diameter, left ventricule end-systolic diameter, and right ventricle diameter compared with the control group. The analysis considering the severity of osteogenesis imperfecta shows that in mild osteogenesis imperfecta, the aortic diameter (p < 0.001), left atrium diameter (p = 0.002), left ventricule end-diastolic diameter (p = 0.001), left ventricule end-systolic diameter (p = 0.026), and right ventricle diameter (p < 0.001) were significantly larger than in the control group. Patients with moderate/severe osteogenesis imperfecta had similar results, with aortic diameter (p < 0.001), left atrium diameter (p < 0.001), left ventricule end-diastolic diameter (p = 0.013), and left ventricule end-systolic diameter (0.004) statistically larger than controls. Twenty-six (48.1%) of the cases had physiological tricuspid regurgitation and in controls this finding was observed in eight (14.8%) (p < 0.001).

CONCLUSION

Children with osteogenesis imperfecta presented cardiac function within the normal pattern, but dimensions of left ventricular dimensions were increased compared to the ones of the controls.

Is HSPG2 a modifier gene for Marfan syndrome?

Marfan syndrome (MFS) is a connective tissue disease caused by variants in the FBN1 gene. Nevertheless, other genes influence the manifestations of the disease, characterized by high clinical variability even within families. We mapped modifier loci for cardiovascular and skeletal manifestations in the mg∆loxPneo mouse model for MFS and the synthenic loci in the human genome. Corroborating our findings, one of those loci was identified also as a modifier locus in MFS patients. Here, we investigate the HSPG2 gene, located in this region, as a candidate modifier gene for MFS. We show a correlation between Fbn1 and Hspg2 expression in spinal column and aorta in non-isogenic mg∆loxPneo mice. Moreover, we show that mice with severe phenotypes present lower expression of Hspg2 than those mildly affected. Thus, we propose that HSPG2 is a strong candidate modifier gene for MFS and its role in modulating disease severity should be investigated in patients.

Retinal and Choroidal Vasculature in Patients with Marfan Syndrome

Purpose

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

Methods

This prospective, case-control, observational study included 48 eyes of 24 patients with a genetic diagnosis of MfS and compared them with 52 eyes of 26 healthy controls. Best-corrected visual acuity, choroidal and retinal thickness measured by spectral domain-optical coherence tomography, retinal and choroidal vasculature characterized by optical coherence tomography angiography, were collected. A genetic counseling was carried out. A transthoracic echocardiogram was performed to evaluate the dimension of the aortic root, the ascending aorta and the left ventricle function and dimensions.

Results

A significant decrease in the superficial and deep retinal capillary plexi vessel density (VD) was evident, such as a decrease in the choriocapillaris plexus VD. In patients with MfS, a negative correlation between left ventricular diameter and the VD of the superficial and deep plexi was observed. Patients with MfS with greater posterior wall and interventricular septum dimensions had lower VD in both plexi (P < 0.05). Moreover, there was a negative correlation between the dimension of the ascending aorta and foveal choriocapillary VD. In patients with MfS, increasing diameter of the ascending aorta was associated with a lower foveal choriocapillary VD (P < 0.05).

Conclusions

The severity of MfS correlates with the impairment of the retinal and choroidal vasculature.

Translational Relevance

Optical coherence tomography angiography may be a reproducible and noninvasive tool to study retinal blood flow in patients with MfS, with potential diagnostic and prognostic value.

Disorders of the Aorta and Aortic Valve in Connective Tissue Diseases

PURPOSE OF REVIEW

The incidence of aortic valve disease in inherited connective tissue disorders is well documented; however, recent studies have only begun to unravel the pathology behind this association. In this review, we aim to describe the etiology, clinical manifestations, management, and prognosis of aortic and aortic valvular disorders that co-exist in a variety of connective tissue diseases. An extensive literature review was performed in PubMed. Articles from 2008 to 2018 were included for review. Predetermined search terms used in PubMed include "aortic manifestation of connective tissue diseases" and "aortic valve disorders in rheumatologic disease."

RECENT FINDINGS

Manifestations of aortic valve disease in the context of connective tissue disorders include valvular stenosis, regurgitation, and/or thoracic aortic aneurysms. Both inherited and inflammatory connective tissue disorders contribute to aortic valve damage with increased susceptibility associated with specific gene variants. Anti-inflammatory and immunosuppressive therapies have demonstrated beneficial results in Marfan's syndrome, Behcet disease, rheumatoid arthritis, ankylosing spondylitis, and systemic sclerosis, often leading to remission. Yet, such therapy is less effective in other disorders compared to alternative treatments such as surgical intervention. Additionally, regular echocardiographic studies should be recommended to those suffering from these disorders, especially those at higher risk for cardiovascular involvement. Given the rates of relapse with immunosuppressants, even following aortic valve replacement, further studies are needed to determine if certain dosing and/or combinations of immunosuppressants could be given to those diagnosed with connective tissue diseases to prevent progression of aortic valve involvement.