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Loeys-Dietz syndrome type 1 (LDS1) is caused by a mutation in the transforming growth factor-beta receptor 1 (TGFBR1) gene. We previously characterized the oral and dental anomalies in a cohort of individuals diagnosed with LDS and showed that LDS1 had a high frequency of oral manifestations, and most affected individuals had enamel defects. However, dentin anomalies were not apparent in most patients in the cohort. In this cohort, we had identified dentin anomalies in a patient with LDS1, harboring mutation TGFBR1 c.1459C>T (p.Arg487Trp), and in this report, we present clinical and radiographic findings to confirm the dentin anomaly. The proband had gray-brown discoloration of most teeth typical for dentinogenesis imperfecta (DI). A radiographic exam revealed obliterated or very narrow pulp canals, with maxillary anterior teeth being affected more than the posterior teeth. The son of the proband, who also has the same mutation variant, had a history of DI affecting the primary teeth; however, his permanent teeth were normal in appearance at the time of exam. TGFBR1 is expressed by odontoblasts throughout tooth development and deletion of TGFBR1 in mouse models is known to affect dentin development. In this report, we present a rare case of abnormal dentin in two individuals with LDS1. These dental anomalies may be the first obvious manifestation of a life-threatening systemic disease and demonstrate the variable and multi-organ phenotypic effects in rare diseases.

Objective: Loeys-Dietz syndrome (LDS) is associated with a higher risk of aortic dissections (ADs) during pregnancy and postpartum. However, there is limited evidence about the perinatal management of LDS patients who have undergone prophylactic aortic root replacements (ARRs) before conception. Case report: We present the case of a 28-year-old nulliparous pregnant woman with LDS with a pathogenic variant within exon 5 of TGFBR2 (c.1379G > T, p.[Arg460Leu]), who underwent an ARR at 20 years of age. Cardiac echocardiography did not show any significant changes in the aorta during pregnancy, and her blood pressure remained normal. She had a cesarean section at 37 weeks of gestation. She developed an acute Stanford type B AD extending from the aortic arch to the infrarenal aorta 8 days postpartum and underwent a total arch replacement. Conclusion: This case report suggests that patients with LDS after prophylactic ARRs still possess a risk for Stanford type B ADs.

Loeys-Dietz syndrome (LDS) is a connective tissue disorder with associated systemic vasculopathies including intracranial arterial aneurysm formation and dissections. LDS is a relatively less well-known entity compared with other connective tissue disorders, such as Ehlers-Danlos or Marfan syndrome, and consequently experience in the management of the associated intracranial aneurysms is suboptimal. We present a case of surgical clipping of a middle cerebral artery aneurysm in a patient with LDS. A 46-year-old female with LDS (type III) was found to have a right middle cerebral artery (MCA) bifurcation aneurysm following vascular screening. The decision was made to surgically clip the aneurysm after consultation in our neurovascular multidisciplinary team meeting. A standard right pterional craniotomy was performed and the aneurysm was secured with 2 straight Sugita clips. The temporal M2 branch was noted to be thin walled and this prompted application of the second tandem clip, rather than risk re-positioning the initial clip. In our case, the MCA aneurysm neck was robust enough to take a clip without any complications, and therefore we suggest that the presence of LDS is not an absolute contra-indication to perform open craniotomy and clipping.

Background: Loeys-Dietz syndrome (LDS) is an inherited disorder predisposing individuals to thoracic aortic aneurysm and dissection. Currently, there are no medical treatments except surgical resection. Although the genetic basis of LDS is well-understood, molecular mechanisms underlying the disease remain elusive, impeding the development of a therapeutic strategy. In addition, aortic smooth muscle cells (SMCs) have heterogenous embryonic origins, depending on their spatial location, and lineage-specific effects of pathogenic variants on SMC function, likely causing regionally constrained LDS manifestations, have been unexplored.Methods: We identified an LDS family with a dominant pathogenic variant in the TGFBR1 gene (TGFBR1A230T) causing aortic root aneurysm and dissection. To accurately model the molecular defects caused by this mutation, we used human induced pluripotent stem cells from a subject with normal aorta to generate human induced pluripotent stem cells carrying TGFBR1A230T, and corrected the mutation in patient-derived human induced pluripotent stem cells using CRISPR-Cas9 gene editing. After their lineage-specific SMC differentiation through cardiovascular progenitor cell (CPC) and neural crest stem cell lineages, we used conventional molecular techniques and single-cell RNA sequencing to characterize the molecular defects. The resulting data led to subsequent molecular and functional rescue experiments using activin A and rapamycin.Results: Our results indicate the TGFBR1A230T mutation impairs contractile transcript and protein levels, and function in CPC-SMC, but not in neural crest stem cell-SMC. Single-cell RNA sequencing results implicate defective differentiation even in TGFBR1A230T/+ CPC-SMC including disruption of SMC contraction and extracellular matrix formation. Comparison of patient-derived and mutation-corrected cells supported the contractile phenotype observed in the mutant CPC-SMC. TGFBR1A230T selectively disrupted SMAD3 (SMAD family member 3) and AKT (AKT serine/threonine kinase) activation in CPC-SMC, and led to increased cell proliferation. Consistently, single-cell RNA sequencing revealed molecular similarities between a loss-of-function SMAD3 mutation (SMAD3c.652delA/+) and TGFBR1A230T/+. Last, combination treatment with activin A and rapamycin during or after SMC differentiation significantly improved the mutant CPC-SMC contractile gene expression and function, and rescued the mechanical properties of mutant CPC-SMC tissue constructs.Conclusions: This study reveals that a pathogenic TGFBR1 variant causes lineage-specific SMC defects informing the etiology of LDS-associated aortic root aneurysm. As a potential pharmacological strategy, our results highlight a combination treatment with activin A and rapamycin that can rescue the SMC defects caused by the variant. [ABSTRACT FROM AUTHOR]

Background: Familial exudative vitreoretinopathy (FEVR) is an inherited retinal disorder with high genetic heterogeneity, and it is characterized by a defect in the development of the retinal vascular system. Loeys-Dietz syndrome (LDS) is an autosomal dominant systemic connective tissue disorder that is caused by mutations in the genes related to transforming growth factor signaling systems including the TGFBR2 gene. Two earlier studies reported that patients with LDS from mutations in the TGFBR2 gene were associated with FEVR-like retinal phenotype. The purpose of this study was to determine the characteristics of a case of FEVR without systemic abnormalities who had a mutation in the TGFBR2 gene. Materials and Methods: The clinical appearances and surgical outcomes were determined from the medical records. Genetic analysis was performed by whole exome sequencing. Results: A 15-year-old boy was diagnosed with FEVR by the appearance of the peripheral retina of both eyes and a retinal detachment in the left eye. Whole exome sequencing revealed a heterozygous deletion mutation in the TGFBR2 gene. A de novo mutation was confirmed by examining the family members. No systemic abnormalities were detected in the patient including those associated with LDS. Conclusions: FEVR can be associated with a TGFBR2 mutation without showing signs of LDS. [ABSTRACT FROM AUTHOR]

Loeys-Dietz syndrome (LDS) is a rare autosomal dominant disorder and a continuum in which affected individuals may have various combinations of clinical features. This group of patients are at high risk of developing cardiovascular conditions. The purpose of this paper is to discuss the dental management of a four-year-old girl with LDS. Successful treatment was performed under GA after carrying out thorough medical investigations including cardiovascular health status, and cervical spine assessment. Syndrome patients that are at high risk of medical complications should receive early referrals to Pediatric Dentists to avoid complicated treatments. [ABSTRACT FROM AUTHOR]

Aims We aimed to assess the prevalence of mitral annulus disjunction (MAD) and to explore the association with aortic disease and mitral valve surgery in patients with Marfan syndrome (MFS) and Loeys–Dietz syndrome (LDS). Methods and results We included consecutive MFS patients fulfilling Revised Ghent Criteria and LDS patients fulfilling Loeys–Dietz Revised Nosology. MAD was identified by echocardiography and was quantified as the longitudinal distance from the ventricular myocardium to the hinge point of the posterior mitral leaflet. Aortic events were defined as aortic dissection or prophylactic aortic surgery. We recorded the need of mitral valve surgery including mitral valve repair or replacement. We included 168 patients (103 with MFS and 65 with LDS). The prevalence of MAD was 41%. MAD was present in all age groups. Aortic events occurred in 112 (67%) patients (27 with dissections and 85 with prophylactic surgical interventions). Patients with MAD were younger at aortic event than those without MAD (log rank = 0.02) Patients with aortic events had greater MAD distance in posterolateral wall [8 (7–10) mm vs. 7 (6–8) mm, P  = 0.04]. Mitral events occurred more frequently in patients with MAD (P  < 0.001). Conclusion MAD was highly prevalent in patients with MFS and LDS. MAD was a marker of severe disease including aortic events at younger age and need of mitral valve surgery. Screening patients with MFS an LDS for MAD may provide prognostic information and may be relevant in planning surgical intervention. Detection of MAD in patients with MFS and LDS may infer closer clinical follow-up from younger age. [ABSTRACT FROM AUTHOR]

To improve the knowledge about physical exercise in patients with Hereditable Thoracic Aortic Disease, insight to the patient perspectives is necessary. The aim of this study was to explore aspects related to physical exercise as highlighted by the patients themselves. Focus group interviews with 36 people with Marfan syndrome, Loeys-Dietz syndrome and vascular Ehlers Danlos syndrome were conducted. Inductive systematic condensation analysis was performed. Four themes related to physical exercise were elucidated by the participants: (1) Being diagnosed. (2) Considerations of physical exercise. (3) Body image and function. (4) Future perspectives. The four themes are mutually interrelated in terms of barriers, facilitators and strategies for dealing with physical exercise. Our findings indicate that the participants experience exercise as a consistent dilemma between what is healthy and what is risky. Inconsistent professional advice, non-engaging activities, unpredictable health conditions and a fear of exercising were factors that may contribute to inactivity and a sedentary lifestyle. The complexity and existential internal conflict related to physical exercise seemed to be a huge dilemma among persons with Hereditable Thoracic Aortic Disease. The balance between safe and healthy activities should be a research priority in these groups. Physical activity and exercise pose a difficult dilemma for patients with Hereditable Thoracic Aortic Disease, in terms of what is healthy and what is dangerous. People with Hereditable Thoracic Aortic Disease need help to minimize concern, stress and anxiety associated with exercise. Individualized adapted programs including physical, psychological and social rehabilitation goals are most likely to be successful in encouraging exercise in these patient groups. [ABSTRACT FROM AUTHOR]

Cardiovascular involvement in pediatric patients with connective tissue disease (CTD) is life-threatening, with aortic root dilatation being the most prevalent cardiovascular abnormality. We attempted to determine long-term outcomes of valve-sparing root replacement (VSRR) in this group, including cardiovascular reoperations for aortic aneurysm and dissection. We conducted a retrospective analysis of pediatric patients with CTD who received VSRR in a single center from 2002 to 2021. The primary end point was a composite event of all-cause death and cardiovascular reoperations. The median follow-up duration was 8.3 years, with a maximum of 20.7 years. The median age of 24 pediatric patients who had VSRR was 14.4 years. Marfan syndrome and Loeys–Dietz syndrome affected 19 (79.2%) and 5 (20.8%) patients, respectively. There was no early death. The 15-year survival rate was 91.7%. At 10 years after VSRR, the cumulative incidence of reoperation for aortic regurgitation was 15.6%, and for aortic aneurysm or dissection, it was 29.1%. The 10-year rate of freedom from the primary end point was 53.1%. The Cox multivariable analysis revealed younger age at surgery (hazard ratio, 1.279; 95% confidence interval, 1.086-1.505; P =. 003) and VSRR before 13 years of age (hazard ratio, 5.005; 95% confidence interval, 1.146−21.850; P =.032) as independent prognostic factors for the primary endpoint. VSRR for aortic root dilatation in pediatric patients with CTD demonstrated good long-term survival and low reoperation rates for aortic regurgitation. However, several patients developed later aortic aneurysm or dissection, and careful surveillance may be required, particularly in those who received VSRR at younger age. [Display omitted] [ABSTRACT FROM AUTHOR]

Surgery for Stanford type A aortic dissection (TAAD) is associated with an increased risk of late aortic reoperations due to degeneration of the dissected aorta. The subjects of this analysis were 990 TAAD patients who survived surgery for acute TAAD and had complete data on the diameter and dissection status of all aortic segments. After a mean follow-up of 4.2 ± 3.6 years, 60 patients underwent 85 distal aortic reoperations. Ten-year cumulative incidence of distal aortic reoperation was 9.6%. Multivariable competing risk analysis showed that the maximum preoperative diameter of the abdominal aorta (SHR 1.041, 95%CI 1.008–1.075), abdominal aorta dissection (SHR 2.133, 95%CI 1.156–3.937) and genetic syndromes (SHR 2.840, 95%CI 1.001–8.060) were independent predictors of distal aortic reoperation. Patients with a maximum diameter of the abdominal aorta >30 mm and/or abdominal aortic dissection had a cumulative incidence of 10-year distal aortic reoperation of 12.0% compared to 5.7% in those without these risk factors (adjusted SHR 2.076, 95%CI 1.062–4.060). TAAD patients with genetic syndromes, and increased size and dissection of the abdominal aorta have an increased the risk of distal aortic reoperations. A policy of extensive surgical or hybrid primary aortic repair, completion endovascular procedures for aortic remodeling and tight surveillance may be justified in these patients. Trial registration: ClinicalTrials.gov Identifier: NCT04831073. • Distal aortic reoperations may be required after surgery for TAAD. • Genetic syndromes increase the risk of distal aortic reoperation. • Distal aortic reoperations are more frequent when the abdominal aorta is enlarged and/or dissected. • These conditions may justify extensive primary repair and completion procedures. [ABSTRACT FROM AUTHOR]

Abstract Background Loeys-Dietz syndrome (LDS) is a rare connective tissue disorder for which 6 genes in the TGF-β pathway have been identified as causative. With the widespread use of genetic testing, the range of known clinical and genetic profiles has broadened, but these features have not been fully elucidated thus far. Methods and results Using gene panel sequencing or whole exome sequencing, we identified 54 unique rare variants in LDS genes in 57 patients with thoracic aneurysms/dissections, including 27 pathogenic mutations (P + LP) and 27 variants of unknown significance (VUSLP + VUS). Genotype-phenotype correlation analysis revealed that carriers with P/LP/ VUSLP variants in TGFBR1/TGFBR2/SMAD3 genes had significantly more severe cardiovascular features (cardiovascular death/dissection) than carriers with VUSs in these 3 genes at an early age and had less favorable event-free survival. Additionally, carriers with VUS in combination with other risk factors, such as hypertension, might be prone to developing an aortic dissection, as indicated by the fact that 5/8 (62.5%) patients with VUSs in our cohort developed aortic dissections in the presence of hypertension, compared with 25.0% (3/12) in the absence of hypertension (p = 0.047). Conclusions To date, this was the largest cohort of LDS patients ever reported in China, and the present study expanded the known mutation and phenotypic spectra of LDS, which might help refine our knowledge of LDS.

[Display omitted] [ABSTRACT FROM AUTHOR]

Loeys-Dietz syndrome is a recently described connective tissue disorder with a natural history of extreme vessel tortuosity and aggressive arterial aneurysm formation and rupture. This is the case of a 23-year-old woman with a large, dysplastic cavernous aneurysm who had successful endovascular treatment by flow diversion with the Pipeline embolisation device. Ten-month follow-up demonstrated complete aneurysm occlusion and curative reconstruction of the parent vessel without evidence of vessel injury or dissection. Endovascular treatment with flow-diverting devices is a valid treatment option and can be performed safely and effectively in this complex patient population.

Concomitant Loeys-Dietz syndrome (LDS) and hematologic malignancies are exceptionally rare. This is the first report of a patient operated on for aortic root dilation who had been previously diagnosed with LDS and B-cell-lymphoma. After completion of chemotherapy and complete remission, an elective valve-sparing aortic root replacement (using the David-V method) was performed. Due to the positive family history, pre-operative genetic counseling was conducted, and revealed LDS with a TGFBR1 (transforming growth factor beta receptor type I) mutation in 6 probands of the family, albeit in 1 of them posthumously. This missense mutation has been previously described in relation to aortic dissection, but a causative relationship to malig-nancy has so far neither been proposed nor proven.

Loeys–Dietz syndrome (LDS) is a rare autosomal-dominant disorder of the connective tissue with some typical vascular findings, skeletal manifestations, craniofacial features, and cutaneous findings with a wide phenotypic spectrum. Six different genes are involved in LDS and the diagnosis is based on the identification of a heterozygous pathogenic variant in TGFBR1, TGFBR2, SMAD3, TGFB2, TGFB3, or SMAD2 in children with suggestive findings. These genes distinguish LDS into six classes (LDS1–LDS6, respectively). Delay in diagnosis of Loeys–Dietz syndrome may be associated with an adverse prognosis due to a very high augmented risk of early complications such as aortic or vascular rupture. The present report describes a case of an early diagnosis of LDS in a neonate with cleft soft palate and aortic root dilatation.

Abstract Mitral valve prolapse (MVP) is a commonly occurring heart condition defined by enlargement and superior displacement of the mitral valve leaflet(s) during systole. Although commonly seen as a standalone disorder, MVP has also been described in case reports and small studies of patients with various genetic syndromes. In this review, we analyzed the prevalence of MVP within syndromes where an association to MVP has previously been reported. We further discussed the shared biological pathways that cause MVP in these syndromes, as well as how MVP in turn causes a diverse array of cardiac and noncardiac complications. We found 105 studies that identified patients with mitral valve anomalies within 18 different genetic, developmental, and connective tissue diseases. We show that some disorders previously believed to have an increased prevalence of MVP, including osteogenesis imperfecta, fragile X syndrome, Down syndrome, and Pseudoxanthoma elasticum, have few to no studies that use up‐to‐date diagnostic criteria for the disease and therefore may be overestimating the prevalence of MVP within the syndrome. Additionally, we highlight that in contrast to early studies describing MVP as a benign entity, the clinical course experienced by patients can be heterogeneous and may cause significant cardiovascular morbidity and mortality. Currently only surgical correction of MVP is curative, but it is reserved for severe cases in which irreversible complications of MVP may already be established; therefore, a review of clinical guidelines to allow for earlier surgical intervention may be warranted to lower cardiovascular risk in patients with MVP.

Importin 8, encoded by IPO8 , is a ubiquitously expressed member of the importin-β protein family that translocates cargo molecules such as proteins, RNAs, and ribonucleoprotein complexes into the nucleus in a RanGTP-dependent manner. Current knowledge of the cargoes of importin 8 is limited, but TGF-β signaling components such as SMAD1–4 have been suggested to be among them. Here, we report that bi-allelic loss-of-function variants in IPO8 cause a syndromic form of thoracic aortic aneurysm (TAA) with clinical overlap with Loeys-Dietz and Shprintzen-Goldberg syndromes. Seven individuals from six unrelated families showed a consistent phenotype with early-onset TAA, motor developmental delay, connective tissue findings, and craniofacial dysmorphic features. A C57BL/6N Ipo8 knockout mouse model recapitulates TAA development from 8–12 weeks onward in both sexes but most prominently shows ascending aorta dilatation with a propensity for dissection in males. Compliance assays suggest augmented passive stiffness of the ascending aorta in male Ipo8 −/− mice throughout life. Immunohistological investigation of mutant aortic walls reveals elastic fiber disorganization and fragmentation along with a signature of increased TGF-β signaling, as evidenced by nuclear pSmad2 accumulation. RT-qPCR assays of the aortic wall in male Ipo8 −/− mice demonstrate decreased Smad6/7 and increased Mmp2 and Ccn2 (Ctgf) expression, reinforcing a role for dysregulation of the TGF-β signaling pathway in TAA development. Because importin 8 is the most downstream TGF-β-related effector implicated in TAA pathogenesis so far, it offers opportunities for future mechanistic studies and represents a candidate drug target for TAA. [ABSTRACT FROM AUTHOR]

Dysregulated transforming growth factor TGF-β signaling underlies the pathogenesis of genetic disorders affecting the connective tissue such as Loeys-Dietz syndrome. Here, we report 12 individuals with bi-allelic loss-of-function variants in IPO8 who presented with a syndromic association characterized by cardio-vascular anomalies, joint hyperlaxity, and various degree of dysmorphic features and developmental delay as well as immune dysregulation; the individuals were from nine unrelated families. Importin 8 belongs to the karyopherin family of nuclear transport receptors and was previously shown to mediate TGF-β-dependent SMADs trafficking to the nucleus in vitro. The important in vivo role of IPO8 in pSMAD nuclear translocation was demonstrated by CRISPR/Cas9-mediated inactivation in zebrafish. Consistent with IPO8's role in BMP/TGF-β signaling, ipo8 −/− zebrafish presented mild to severe dorso-ventral patterning defects during early embryonic development. Moreover, ipo8 −/− zebrafish displayed severe cardiovascular and skeletal defects that mirrored the human phenotype. Our work thus provides evidence that IPO8 plays a critical and non-redundant role in TGF-β signaling during development and reinforces the existing link between TGF-β signaling and connective tissue defects. [ABSTRACT FROM AUTHOR]

Progressive aortic dilation is common in Marfan syndrome (MFS) and Loeys–Dietz syndrome (LDS). Risk factors for progression are poorly understood. Normal variation in the aortic root (AoR) rotational position relative to the left ventricular base may impact this risk. We aimed to assess the relationship between the rotational position of the AoR and aortic dimensions in this population. Patients with a genetic diagnosis of MFS or LDS were included. AoR and ascending aorta (AAo) dimensions were measured from the first and most recent transthoracic echocardiogram. The AoR rotational angle was measured in the parasternal short-axis plane in diastole. Linear regression was used to study the correlation between AoR rotation angle and aortic dimensions. 53 MFS and 14 LDS patients were included (age 11.5 ± 5.8 years at first TTE and 21.2 ± 7.2 years at most recent, 68% male). The mean indexed AoR and AAo values were 2.26 ± 0.58 cm/m2 and 1.64 ± 0.35 cm/m2 at the first TTE and 1.98 ± 0.39 cm/m2 and 1.45 ± 0.25 cm/m2 at the most recent TTE, respectively. The mean AoR rotational angle was 8 ± 14°. AoR rotational angle was central (− 9 to + 14°) in 42, clockwise (≥ + 15°) in 19, and counterclockwise (≤ −10°) in 6. The six outliers with counterclockwise position were excluded. There was a positive association between the AoR rotation angle and most recent TTE indexed AoR (r2 = 0.08, p = 0.02) and AAo sizes (r2 = 0.08, p = 0.02). There was no association between AoR rotational angle and rate of change in indexed AoR size (p = 0.8). There was a positive association between AoR rotation angle and rate of change in indexed AAo size (r2 = 0.10, p = 0.01). There is an association between clockwise rotational position of the AoR and increased AoR and AAo dimensions in children and young adults with MFS and LDS patients. The rotational position of the AoR may guide follow-up in these patient populations. However, this potential risk factor for dilation warrants further investigation. [ABSTRACT FROM AUTHOR]

We present a 14-year-old boy with Loey–Dietz syndrome with severe mitral regurgitation, pectus excavatum and scoliosis. The Haller index was 25. The heart was displaced into the left hemithorax. The right inferior pulmonary vein was very close to the sternum and vertebral body. Single-stage surgery was performed. An osseo-myo-cutaneous pedicled flap was created by sterno-manubrial junction dislocation and rib resection with bilateral internal mammary arteries supplying the flap. Cardiopulmonary bypass and mitral valve replacement was performed. The defect was bridged with three straight plates. The flap was laid on top and anchored. Early outcome at three months was good. [ABSTRACT FROM AUTHOR]

Background: Patients with connective tissue diseases are at high lifetime risk of developing thoracic aortic aneurysms (TAAs) due to defects in extracellular matrix composition which compromise the structural integrity of the aortic wall. It is vital to identify and manage aneurysms early to prevent fatal complications such as dissection or rupture. Method: This review synthesises information obtained from a thorough literature search regarding the pathophysiology of TAAs in those with heritable connective tissue diseases (HCTDs), the investigations for timely diagnosis and current operative strategies. Results: Major complications of open repair (OR) include pneumonia (32%), haemorrhage (31%) and tracheostomy (18%), with a minor risk of vocal cord paresis (9%). For thoracic endovascular aortic repair (TEVAR), high rates of endoleak were documented (38‐66.6%). Reintervention rates for TEVAR are also high at 38‐44%. Mortality rates were documented as 25% for open repair and vary from 14% to 44% for TEVAR. Conclusion: OR remains the mainstay of surgical management. While TEVAR use is expanding, it remains the alternative choice due to concerns over endograft durability, limited long‐term outcome data and the lack of high‐quality evidence regarding its use in HCTD patients. [ABSTRACT FROM AUTHOR]

Loeys–Dietz syndrome is a recently described condition which causes cardiovascular, craniofacial, neurocognitive and skeletal abnormalities due to mutations in components of the transforming growth factor-β signalling pathway. Associated vascular abnormalities include vessel tortuosity and an increased incidence of vascular dissection. Pregnancy increases the risk of aortic dissection compared to non-pregnant individuals and an underlying condition such as Loeys–Dietz syndrome increases this further. While aortic dissection is well described in pregnancy in Loeys–Dietz syndrome, some women can have uncomplicated deliveries, particularly when the risks of the condition are actively managed. Such pregnancies should be considered high-risk, and women should be counselled and managed accordingly. Here we describe two pregnancies in one woman, both with successful outcomes, followed by a summary of the key management principles. [ABSTRACT FROM AUTHOR]

Loeys-Dietz syndrome (LDS) is a very rare connective tissue disorder with autosomal dominant inheritance, characterized by the involvement of the cardiovascular, musculoskeletal, and cutaneous systems, along with dysmorphic facial features. Currently, there are limited data regarding this disease. This case presents a clinical observation of a 17-year-old boy with acute onset of sensorimotor paraparesis and genetically confirmed LDS. The predominant symptoms of LDS include arterial aneurysms, arterial tortuosity, hypertelorism, and bifid uvula. However, this constellation of symptoms is not found in all patients with the disease. Genetic confirmation is essential for an accurate diagnosis. The prognosis for LDS differs from its mimics, such as Marfan syndrome, Beals syndrome, Ehlers-Danlos syndrome, and Shprintzen-Goldberg syndrome. Management of the disease warrants a multidisciplinary approach to address its various manifestations. Such an approach can help increase the life expectancy and improve the quality of life for these patients., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Parida et al.)

Hereditary aortic aneurysms and dissections, such as Marfan syndrome, differ in that they occur in younger patients without generally recognized risk factors, have a predilection for the thoracic rather than the abdominal aorta, and are at risk for dissection even at smaller aortic diameters. Early diagnosis, careful follow-up, and early intervention, such as medication to reduce aortic root growth and prophylactic aortic replacement to prevent fatal aortic dissection, are essential for a better prognosis. Molecular genetic testing is extremely useful for early diagnosis. However, in actual clinical practice, the question often arises as to when and to which patient genetic testing should be offered since the outcome of the tests can have important implications for the patient and the relatives. Pre- and post-test genetic counseling is essential for early intervention to be effective. (This article is a secondary translation of Jpn J Vasc Surg 2023; 32: 261-267.)., (@ 2024 The Editorial Committee of Annals of Vascular Diseases.)

Loeys-Dietz syndrome (LDS) is a connective tissue disorder with features including, but not limited to, aortic dissections, skeletal abnormalities, and craniofacial defects. However, considering its relatively recent discovery, there are still many unknowns about LDS. The extent of a connective tissue disorder like LDS is yet to be defined throughout the various organ systems, including the gastrointestinal system. Connective tissue disorders have been found to have higher associations with certain conditions, like constipation. In a similar manner, LDS may increase the propensity for developing uncommon gastrointestinal manifestations, like primary small bowel volvulus. A volvulus is defined as an abnormal rotation of the small bowel segment along the axis of its mesentery. Primary small bowel volvulus is differentiated from secondary small bowel volvulus by its nature of origin: primary small bowel volvulus occurs as an independent spontaneous occurrence, whereas secondary small bowel volvulus is secondary to the presence of adhesions, diverticular disease, or abdominal masses. In this case report, we highlight a potential gastrointestinal manifestation of LDS with the occurrence of a primary small bowel volvulus in a young adult male diagnosed with LDS. The patient experienced acute primary small bowel volvulus 14 days into his stay, which may have been influenced by this newfound connective tissue disorder., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Yang et al.)

Rationale: Pathogenic (P)/likely pathogenic (LP) SMAD3 variants cause Loeys-Dietz syndrome type 3 (LDS3), which is characterized by arterial aneurysms, dissections and tortuosity throughout the vascular system combined with osteoarthritis., Objectives: Investigate the impact of P/LP SMAD3 variants with functional tests on patient-derived fibroblasts and vascular smooth muscle cells (VSMCs), to optimize interpretation of SMAD3 variants., Methods: A retrospective analysis on clinical data from individuals with a P/LP SMAD3 variant and functional analyses on SMAD3 patient-derived VSMCs and SMAD3 patient-derived fibroblasts, differentiated into myofibroblasts., Results: Individuals with dominant negative (DN) SMAD3 variant in the MH2 domain exhibited more major events (66.7% vs. 44.0%, P = 0.054), occurring at a younger age compared to those with haploinsufficient (HI) variants. The age at first major event was 35.0 years [IQR 29.0-47.0] in individuals with DN variants in MH2, compared to 46.0 years [IQR 40.0-54.0] in those with HI variants (P = 0.065). Fibroblasts carrying DN SMAD3 variants displayed reduced differentiation potential, contrasting with increased differentiation potential in HI SMAD3 variant fibroblasts. HI SMAD3 variant VSMCs showed elevated SMA expression and altered expression of alternative MYH11 isoforms. DN SMAD3 variant myofibroblasts demonstrated reduced extracellular matrix formation compared to control cell lines., Conclusion: Distinguishing between P/LP HI and DN SMAD3 variants can be achieved by assessing differentiation potential, and SMA and MYH11 expression. The differences between DN and HI SMAD3 variant fibroblasts and VSMCs potentially contribute to the differences in disease manifestation. Notably, myofibroblast differentiation seems a suitable alternative in vitro test system compared to VSMCs., (© The Author(s) 2024. Published by Oxford University Press.)

Loeys–Dietz syndrome (LDS) is a rare connective tissue genetic disorder that is caused by a pathogenic variant in genes of transforming growth factor (TGF) beta receptor 1 (TGFBR1), TGFBR2, mothers against decapentaplegic homolog 2 (SMAD2), SMAD3, TGFB2, or TGFB3. It is characterized by aggressive vascular pathology, aneurysms, arterial tortuosity, bifid uvula, hypertelorism, and cleft palate. Here we present a 42-year-old female patient with LDS. The patient underwent rapidly progressing artery aneurysms and life-threatening aortic dissection. Spontaneous fracture of the first metatarsal bone was noted in her medical record. Physical examination revealed a delayed wound healing on her left abdomen. Considering these clinical manifestations, we speculated that there was a genetic defect in the connective tissue, which provides strength and flexibility to structures such as bones, skins, ligaments, and blood vessels. Thus, whole exome sequencing (WES) was performed on the proband and revealed a heterozygous missense pathogenic variant (c.1613T > C/p.Val538Ala) in TGFBR2, which was a de novo variant in the proband as confirmed by the segregation analysis in parental samples. Although this variant was discovered and associated with the phenotype of LDS previously, the pathogenicity of the variant had not been confirmed by cellular functional assay yet. To further validate the effects of the variant in vitro, we assessed the canonical TGF-β signaling pathway in mutant cells. Our results showed that the p.Val538Ala variant significantly decreased TGF-β-induced gene transcription and the phosphorylation of Smad2, which were consistent with other pathogenic variants of TGFBR2. In conclusion, this study demonstrates that the p.Val538Ala pathogenic variant in TGFBR2 leads to aberrant TGF-β signaling and LDS in this patient.

Abstract Background Pathogenic SMAD3 variants are responsible for a cardiovascular phenotype, mainly thoracic aortic aneurysms and dissections. Precocious identification of the vascular risk such as aortic dilatation in mutated patients has a major impact in terms of management, particularly to avoid dissection and sudden death. These vascular damages are classically associated with premature osteoarthritis and skeletal abnormalities. However, variable expressivity and incomplete penetrance are common with SMAD3 variants. Methods To investigate the clinical variability observed within SMAD3 patients, we reviewed the phenotypic and genetic data of 22 new patients from our Centre and of 133 patients reported in the literature. From this cohort of 155 mutated individuals, we first aimed to delineate an estimated frequency of the main clinical signs associated with SMAD3 pathogenic variants and, then, to look for genotype‐phenotype correlations, mainly to see if the aortic phenotype (AP) could be predicted by the SMAD3 variant type. Results We showed, herein, the absence of correlation between the SMAD3 variant type and the occurrence of an AP in patients. Conclusion Therefore, this report brings additional data for the genotype‐phenotype correlations of SMAD3 variants and the need to explore in more detail the effects of genetic modifiers that could influence the phenotype.

INTRODUCTION Marfan syndrome (MFS) and related connective tissue disorders (CTDs) are increasingly recognised. Genetic testing has greatly improved the diagnostic outcome/power over the last two decades. In this study we describe a multicentre cohort of adults with MFS and related CTDs, with a particular focus on results from genetic testing. METHODS All patients with MFS and related CTDs were identified from the databases of five centres in the canton of Zurich. Echocardiographic and clinical findings including systemic Marfan score, use of medication and genetic results were retrospectively analysed. MFS was diagnosed using the revised Ghent criteria (including FBN1 genetic testing if available); other CTDs (Loeys-Dietz syndrome) were diagnosed by genetic testing only. RESULTS A cohort of 103 patients were identified (62 index patients, 41 relatives of family members): 96 patients with MFS and 7 patients with other CTD, 54 males (52%), median age 23 years (range 1–75). The median systemic Marfan score was 5 (range 0–18). Only 40 patients (40/103, 39%) fulfilled criteria for systemic involvement (≥7 points). A history of aortic dissection was present in 14 out of 103 patients (14%). Echocardiographic data were available for all: aortic root enlargement (Z-score ≥2 in adults, Z-score ≥3 in children) was found in 49 patients (48%) and mitral valve prolapse in 64 (62%). Genetic testing had been performed in 80 patients (78%); FBN1 mutations were present in 69 patients (86%); other pathogenic mutations could be identified in seven patients (9%); no disease-causing mutation was found in four patients, three of them fulfilling the Ghent criteria of MFS. Of the mutation-positive patients, 33 had a systemic score of ≥7 and 43 had a systemic score of ≥5. Revised Ghent criteria were fulfilled in 70 patients: in 69 patients with FBN1 mutations and 1 patient with another CTD. Recommended treatment (beta-blocker, angiotensin receptor blocker) was taken by 63% of patients. CONCLUSIONS In this cohort a high percentage of patients fulfilling the revised Ghent criteria for MFS underwent genetic testing, often leading to or confirming the diagnosis of MFS. Other CTDs could be discriminated best by genetic testing. With respect to the diagnosis of MFS and related CTDs, the usefulness of the systemic score is limited, showing the importance of genetic testing, which enabled definitive diagnosis in 95% of tested patients. Patient education on medical treatment still has to be improved. (Trial registration no: KEK-ZH-Nr. 2013-0241)

Abstract Background Larsen syndrome is a hereditary disorder characterized by osteochondrodysplasia, congenital large-joint dislocations, and craniofacial abnormalities. The autosomal dominant type is caused by mutations in the gene that encodes the connective tissue protein, filamin B (FLNB). Loeys-Dietz syndrome (LDS) is an autosomal dominant connective tissue disorder characterized by arterial aneurysms, dissections and tortuosity, and skeletal, including craniofacial, manifestations. Mutations in five genes involved in the transforming growth factor beta (TGF-β) signaling pathway cause five types of LDS. Stickler syndrome is a genetically heterogeneous arthro-ophthalmopathy caused by defects in collagen, exhibiting a wide specter of manifestations in connective tissue. A rare case is reported that was diagnosed with all these three hereditary connective tissue disorders. Case presentation A 19 year-old, Norwegian male with a clinical diagnosis of Larsen syndrome and with healthy, non-consanguineous parents attended a reference center for rare connective tissue disorders. Findings at birth were hypotonia, joint hypermobility, hyperextended knees, adductovarus of the feet, cervical kyphosis, craniofacial abnormalities, and an umbilical hernia. From toddlerhood, he required a hearing aid due to combined conductive and sensorineural hearing loss. Eye examination revealed hyperopia, astigmatism, and exotropia. At 10 years of age, he underwent emergency surgery for rupture of an ascending aortic aneurysm. At 19 years of age, a diagnostic re-evaluation was prompted by the findings of more distal aortic dilation, tortuosity of precerebral arteries, and skeletal findings. High throughput sequencing of 34 genes for hereditary connective tissue disorders did not identify any mutation in FLNB, but did identify a de novo missense mutation in TGFBR2 and a nonsense mutation in COL2A1 that was also present in his unaffected father. The diagnosis was revised to LDS Type 2. The patient also fulfills the proposed criteria for Stickler syndrome with bifid uvula, hearing loss, and a known mutation in COL2A1. Conclusion LDS should be considered in patients with a clinical diagnosis of Larsen syndrome, in particular in the presence of arterial aneurysms or tortuosity. Due to genetic heterogeneity and extensive overlap of clinical manifestations, genetic high throughput sequencing analysis is particularly useful for the differential diagnosis of hereditary connective tissue disorders.

Background: Loeys-Dietz syndrome (LDS) is a rare autosomal-dominant connective tissue disorder characterized by arterial aneurysms and vascular friability. Surgical intervention for LDS patients carries significant morbidity and mortality. Currently, the standard management of aortic root pseudoaneurysms is surgical intervention. Case presentation: A 20 year old male with LDS presented with a progressively enlarging ascending aortic aneurysm. He underwent a Bentall-type aortic root replacement complicated by a 20 mm aortic root anastomotic pseudoaneurysm. Due to the patient's high risk for repeat surgical intervention, he underwent successful transarterial coil embolization of his aortic root pseudoaneurysm without complication. Conclusions: Coil embolization may provide an alternative treatment for patients presenting with aortic root pseudoaneurysm who are high risk for traditional surgical treatment, such as those with connective tissue disease. [ABSTRACT FROM AUTHOR]

Background and Purpose: Loeys-Dietz syndrome (LDS) is a connective tissue disorder characterized by arterial aneurysms and dissections. This study sought to assess and describe the arterial changes of the cervical arterial vasculature of such patients, with an emphasis on the carotid bifurcation. Material and Methods: A retrospective review of patients with a known diagnosis of LDS was carried out. The maximum diameters of the external carotid artery (ECA) and internal carotid artery (ICA) origins, common carotid artery (CCA) terminus, maximum transverse and craniocaudal dimensions of the carotid bulb, and bifurcation angle were measured. The presence of a chalice sign was defined as a carotid bifurcation angle of ≥80°. A semi-quantified analysis of vertebral artery tortuosity was completed as well. All measurements were compared to a cohort of age-matched controls. Results: A total of 21 patients with LDS were included. Compared to normal controls, the presence of a chalice sign had 61.9% sensitivity and 100.0% specificity for LDS if present bilaterally; the sensitivity and specificity of a unilateral chalice sign were 66.7% and 82.3%, respectively. Patients with LDS also had significantly higher rates of a bilateral chalice sign compared to patients with vascular Ehlers-Danlos syndrome (vEDS) (61.9% versus 0%, P <0.0001) and patients with Marfan syndrome (61.9% versus 14.3%, P = 0.001). Conclusion: Patients with LDS have characteristic findings of the cervical arterial vasculature that enables them to be distinguished from normal controls as well as patients with connective tissue diseases, such as Marfan syndrome and vEDS; most notably including marked widening of the carotid bifurcation angle in what is proposed to be named the chalice sign. [ABSTRACT FROM AUTHOR]

Objectives: Thoracic endovascular aortic repair (TEVAR) remains controversial in patients with connective tissue disorders given the concern for durability. We report on the largest series to date on outcomes of patients with thoracic aortic disease and connective tissue disorders treated with TEVAR. Methods: The Vascular Quality Initiative registry identified 12 207 patients treated with TEVAR from January 2010 to December 2018, including 102 with Marfans, Ehlers-Danlos, or Loey-Dietz syndrome. Outcomes were analyzed per the Society for Vascular Surgery reporting standards. Results: Median age was 50.6 years (interquartile range: 57.0-75.0), and 62 (60.7%) were male. Eighty-eight (86.3%) patients had Marfan, 9 (8.8%) had Ehlers-Danlos, and 5 (4.9%) had Loey-Dietz syndrome. Twenty-six (25.5%) patients were treated for degenerative aneurysmal disease and 76 (74.5%) patients for type B dissections (33 acute, 31 chronic). Most common indications for interventions in patients with type B dissection were pain (n = 41), aneurysmal degeneration (n = 16), and malperfusion (n = 8), with 3 patients who presented ruptured. There was no significant difference in perioperative complications between acute/chronic dissections and aneurysms (P =.14). Percutaneous access was utilized in 61.7% of patients, with a 2.9% rate of arterial injury requiring reintervention. Follow-up data were available for 75 (73.3%) patients at a mean follow-up of 15.6 months. Overall mortality was 5.3%. There were 30 patients with follow-up endoleak data, and 8 (26.7%) endoleaks were identified. All endoleaks were in patients treated for acute type B dissection, and all resolved after a mean of 2.1 reinterventions. Three patients treated for acute Type B Aortic Dissection (TBAD) had retrograde dissections requiring intervention. Discussion: Thoracic endovascular aortic repair for patients with connective tissue disorders can be performed with low perioperative mortality, spinal cord ischemia, or Cerebrovascular Accident (CVA). On follow-up, acute type B aortic dissections represent a higher risk subgroup with increased rates of endoleak and retrograde dissection. Closer follow-up for these patients and early reintervention may be beneficial. [ABSTRACT FROM AUTHOR]

We sought to develop strategies for management of the aortic arch in patients with Loeys–Dietz syndrome (LDS) through a review of our clinical experience with these patients and a comparison with our experience in patients with Marfan syndrome (MFS). We reviewed hospital and follow-up records of 79 patients with LDS and compared them with 256 patients with MFS who served as reference controls. In the LDS group, 16% of patients presented initially with acute aortic dissection (AAD) (67% type A, 33% type B) or developed AAD during follow-up, compared with 10% of patients with MFS (95% type A, 5% type B). There was no difference between patients with LDS or MFS in need for subsequent arch interventions after aortic root surgery (46% vs 50%, P = 1.0). Among the patients who never had AAD, the need for arch repair at initial root surgery was greater in patients with LDS (5% vs 0.4%, P =.04), as was the need for any subsequent aortic surgery (12% vs 1.3%, P =.0004). Late mortality in patients with LDS after arch repair was greater than in those patients who had no arch intervention (33% vs 6%, P =.007). In the absence of dissection, patients with LDS have a greater rate of arch intervention after root surgery than patients with MFS. After a dissection, arch reintervention rates are similar in the 2 groups. Arch intervention portends greater late mortality in LDS. Findings of the study: The need for subsequent arch interventions after acute aortic dissection (AAD) does not seem to be greater in patients with Loeys–Dietz syndrome (LDS) compared with Marfan syndrome (MFS). In contrast, patients with LDS undergoing elective root repair have an increased risk for subsequent arch interventions, so consideration should be given to complete removal of the distal ascending aorta. [ABSTRACT FROM AUTHOR]

Loeys‐Dietz syndrome (LDS), a connective tissue disorder characterized by its vascular, skeletal, craniofacial, and cutaneous manifestations is caused by mutations in one of six genes (TGFBR1, TGFBR2, SMAD2, SMAD3, TGFB2, and TGFB3). Until recently, all reported cases of LDS have been attributed to heterozygous pathogenic variants in these genes. Here, we report the first case of Loeys‐Dietz syndrome due to SMAD3 biallelic likely pathogenic variants in a 15‐year‐old male with classic Loeys‐Dietz features, including dysmorphic facial features, significant scoliosis, and pectus excavatum, arachnodactyly, severe aortic root dilation, and diffuse arterial tortuosity. His parents are each heterozygous for the likely pathogenic variant and are more mildly affected. To our knowledge, this represents the first reported case of biallelic SMAD3‐related Loeys‐Dietz syndrome and the third case in the literature of biallelic LDS, indicating that there are multiple genetic modes of inheritance underlying this disorder. [ABSTRACT FROM AUTHOR]

Background Loeys–Dietz syndrome (LDS) is a genetic connective tissue disorder, which is characterized by rapid development of aortic and peripheral arterial aneurysms. Loeys–Dietz syndrome has some overlapping phenotypic features with other inherited aortopathies such as Marfan syndrome. However, LDS has a more aggressive vascular course with patient morbidity and mortality occurring at an early age. Case summary We present the rare case of an 11-year-old girl with LDS who underwent valve sparing aortic root replacement at the age of 2.9 years with good results. She had routine follow-up cardiovascular magnetic resonance imaging and was found to have a large aneurysm of the right subclavian artery. After multidisciplinary team discussion, successful surgical resection with prosthetic graft replacement of the right subclavian artery was performed. Discussion This case illustrates that large aneurysms of aortic branches can already develop in childhood and underlines the need for frequent follow-ups including cross-sectional imaging and multidisciplinary team management. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the potential association between imaging features and cardiovascular outcomes in patients with Loeys–Dietz syndrome (LDS). We performed a retrospective cohort study of 36 patients with LDS and described cardiovascular events and imaging data. We observed different clinical courses in patients with LDS, irrespective of the causative gene. Angular or elongated aortic arch geometry correlated with aortic dissection (R =.39, p =.02), occurrence of the first cardiovascular event before 45 years of age (R =.36, p =.03), and the number of operations (R = 0.47, p =.004), but not with age (R = −.05, p =.79) or the causative gene (R = −0.04, p =.79). The incidences of first cardiovascular events at ages 20, 40, and 60 years were 100, 75, and 56%, respectively, in patients with normal aortic arches, and 74, 39, and 21%, respectively, in patients with angular or elongated aortic arches (log‐rank p =.03). Angular or elongated aortic arch geometry is associated with early‐onset of disease and a worse cardiovascular outcome in LDS patients. Large multicenter studies are warranted to elucidate the impact of aortic arch morphology evaluation in clinical practice. [ABSTRACT FROM AUTHOR]

Loeys–Dietz syndrome (LDS) is a rare connective tissue genetic disorder that is caused by a pathogenic variant in genes of transforming growth factor (TGF) beta receptor 1 (TGFBR1), TGFBR2 , mothers against decapentaplegic homolog 2 (SMAD2), SMAD3 , TGFB2 , or TGFB3. It is characterized by aggressive vascular pathology, aneurysms, arterial tortuosity, bifid uvula, hypertelorism, and cleft palate. Here we present a 42-year-old female patient with LDS. The patient underwent rapidly progressing artery aneurysms and life-threatening aortic dissection. Spontaneous fracture of the first metatarsal bone was noted in her medical record. Physical examination revealed a delayed wound healing on her left abdomen. Considering these clinical manifestations, we speculated that there was a genetic defect in the connective tissue, which provides strength and flexibility to structures such as bones, skins, ligaments, and blood vessels. Thus, whole exome sequencing (WES) was performed on the proband and revealed a heterozygous missense pathogenic variant (c.1613T > C/p.Val538Ala) in TGFBR2 , which was a de novo variant in the proband as confirmed by the segregation analysis in parental samples. Although this variant was discovered and associated with the phenotype of LDS previously, the pathogenicity of the variant had not been confirmed by cellular functional assay yet. To further validate the effects of the variant in vitro , we assessed the canonical TGF-β signaling pathway in mutant cells. Our results showed that the p.Val538Ala variant significantly decreased TGF-β-induced gene transcription and the phosphorylation of Smad2, which were consistent with other pathogenic variants of TGFBR2. In conclusion, this study demonstrates that the p.Val538Ala pathogenic variant in TGFBR2 leads to aberrant TGF-β signaling and LDS in this patient. [ABSTRACT FROM AUTHOR]

Disease‐causing variants in TGFB3 cause an autosomal dominant connective tissue disorder which is hard to phenotypically delineate because of the small number of identified cases. The purpose of this retrospective cross‐sectional multicenter study is to elucidate the genotype and phenotype in an international cohort of TGFB3 patients. Eleven (eight novel) TGFB3 disease‐causing variants were identified in 32 patients (17 families). Aortic root dilatation and mitral valve disease represented the most common cardiovascular findings, reported in 29% and 32% of patients, respectively. Dissection involving distal aortic segments occurred in two patients at age 50 and 52 years. A high frequency of systemic features (65% high‐arched palate, 63% arachnodactyly, 57% pectus deformity, 52% joint hypermobility) was observed. In familial cases, incomplete penetrance and variable clinical expressivity were noted. Our cohort included the first described homozygous patient, who presented with a more severe phenotype compared to her heterozygous relatives. In conclusion, TGFB3 variants were associated with a high percentage of systemic features and aortic disease (dilatation/dissection) in 35% of patients. No deaths occurred from cardiovascular events or pregnancy‐related complications. Nevertheless, homozygosity may be driving a more severe phenotype. [ABSTRACT FROM AUTHOR]