Tricuspid valve prolapse as an early predictor for severe phenotype in children with Marfan syndrome.

AIM: In Marfan syndrome, various cardiovascular pathologies, such as aortic dilatation and mitral valve pathologies, already occur in childhood and determine course of the disease. This study aimed to establish additional cardiovascular risk markers for severe Marfan phenotypes. We investigated tricuspid valve prolapse (TVP) and its predictive value for outcome of paediatric Marfan disease. METHODS: In this retrospective, observational cohort study, we identified 130 paediatric Marfan patients (10.7 ± 4.8 years) with FBN1 variants. We divided patients into two groups based on TVP presence and performed a cross-sectional analysis to investigate the association of TVP with other cardiovascular, ocular and systemic pathologies, at first and last visit. A longitudinal analysis was performed with follow-up data. RESULTS: At baseline, patients with TVP had higher incidence of aortic root dilatation (p = 0.013), mitral valve prolapse (p = 0.0001) and systemic manifestations (p = 0.025) than patients without TVP. At follow-up, previous presence of TVP predicted higher probability of aortic root dilatation (p = 0.002), mitral valve prolapse (p = 0.0001) and systemic manifestations (p = 0.002). CONCLUSION: This shows that TVP is linked to both cardiac and extracardiac Marfan manifestations and TVP is an important marker for a disease severity in these children. Therefore, TVP should be assessed routinely using echocardiography in paediatric Marfan patients.

Next-generation sequencing of 32 genes associated with hereditary aortopathies and related disorders of connective tissue in a cohort of 199 patients.

PURPOSE: Heritable factors play an important etiologic role in connective tissue disorders (CTD) with vascular involvement, and a genetic diagnosis is getting increasingly important for gene-tailored, personalized patient management. METHODS: We analyzed 32 disease-associated genes by using targeted next-generation sequencing and exome sequencing in a clinically relevant cohort of 199 individuals. We classified and refined sequence variants according to their likelihood for pathogenicity. RESULTS: We identified 1 pathogenic variant (PV; in FBN1 or SMAD3) in 15 patients (7.5%) and ≥1 likely pathogenic variant (LPV; in COL3A1, FBN1, FBN2, LOX, MYH11, SMAD3, TGFBR1, or TGFBR2) in 19 individuals (9.6%), together resulting in 17.1% diagnostic yield. Thirteen PV/LPV were novel. Of PV/LPV-negative patients 47 (23.6%) showed ≥1 variant of uncertain significance (VUS). Twenty-five patients had concomitant variants. In-depth evaluation of reported/calculated variant classes resulted in reclassification of 19.8% of variants. CONCLUSION: Variant classification and refinement are essential for shaping mutational spectra of disease genes, thereby improving clinical sensitivity. Obligate stringent multigene analysis is a powerful tool for identifying genetic causes of clinically related CTDs. Nonetheless, the relatively high rate of PV/LPV/VUS-negative patients underscores the existence of yet unknown disease loci and/or oligogenic/polygenic inheritance.

The Pulmonary Artery in Pediatric Patients with Marfan Syndrome: An Underestimated Aspect of the Disease.

Aortic root dilatation and its complications are known to be the most important and life limiting features in patients with Marfan syndrome (MFS). Since monitoring of patients, preventive medical and surgical treatments are available nowadays, other MFS pathologies are becoming more relevant for the outcome of the disease. Main pulmonary artery (MPA) dilatation is a cardiac finding, which has not been fully investigated in children. Due to the similarities in tissue composition of the aortic and pulmonary root, MPA dilatation may cause complications and require treatment. In addition, it may be a predictor for severe connective tissue involvement. We retrospectively examined 135 pediatric patients with MFS. 8.1% showed MPA dilatation. MPA dilatation was associated with earlier occurrence of aortic dilatation, mitral valve prolapse, and systemic manifestations of MFS compared with patients without MPA dilatation (p < 0.05). The presence of MPA dilatation was also associated with a higher incidence of ectopia lentis (p < 0.05). Medical treatment was started earlier in MPA dilatation patients than in those without (p < 0.05). We conclude that MPA dilatation is a sign of more severe vascular and connective tissue involvement. Regular examination of the pulmonary artery is essential in MFS to avoid complications. As medical treatment of life threatening MFS events has improved, other features of MFS need to be investigated to improve quality of life.

TGFß level in healthy and children with Marfan syndrome-effective reduction under sartan therapy.

Introduction: Transforming growth factor ß (TGFß) metabolism plays an important role in the pathogenesis of Marfan syndrome (MFS). Accordingly, drug therapy uses TGFß receptor blockade to slow down the cardiovascular manifestations, above all aortic root dilatation. Angiotensin II type 1 receptor blockers (ARBs) have been shown to reduce TGFß levels in adults. Data on childhood are lacking and are now being investigated in the TiGer For Kids study presented here. Methods: We examined 125 children without chronic disease and 31 pediatric Marfan patients with a proven FBN1 variant with regard to TGFß levels. In addition, we measured TGFß levels during the initiation of ARB therapy in pediatric Marfan patients. Results: In children without chronic disease, TGFß levels were found to decrease from childhood to adolescence (p < 0.0125). We could not measure a relevantly increased TGFß level in pediatric Marfan patients. However, we showed a significant suppression of the TGFß level after treatment with ARBs (p < 0.0125) and a renewed increase shortly before the next dose. Discussion: The TGFß level in childhood changes in an age-dependent manner and decreases with age. The TGFß level drops significantly after taking ARBs. Based on our experience and data, a TGFß receptor blockade in childhood seems reasonable. So far, TGFß level cannot be used as an MFS screening biomarker.

Genotype-Phenotype Correlation in Children: The Impact of FBN1 Variants on Pediatric Marfan Care.

Currently, no reliable genotype-phenotype correlation is available for pediatric Marfan patients in everyday clinical practice. We investigated correlations of FBN1 variants with the prevalence and age of onset of Marfan manifestations in childhood and differentiated three groups: missense/in-frame, splice, and nonsense/frameshift variants. In addition, we differentiated missense variants destroying or generating a cysteine (cys-missense) and alterations not affecting cysteine. We categorized 105 FBN1-positive pediatric patients. Patients with cys-missense more frequently developed aortic dilatation (p = 0.03) requiring medication (p = 0.003), tricuspid valve prolapse (p = 0.03), and earlier onset of myopia (p = 0.02) than those with other missense variants. Missense variants correlated with a higher prevalence of ectopia lentis (p = 0.002) and earlier onset of pulmonary artery dilatation (p = 0.03) than nonsense/frameshift, and dural ectasia was more common in the latter (p = 0.005). Pectus excavatum (p = 0.007) appeared more often in patients with splice compared with missense/in-frame variants, while hernia (p = 0.04) appeared earlier in the latter. Findings on genotype-phenotype correlations in Marfan-affected children can improve interdisciplinary therapy. In patients with cys-missense variants, early medical treatment of aortic dilatation seems reasonable and early regular ophthalmologic follow-up essential. Patients with nonsense/frameshift and splice variants require early involvement of orthopedic specialists to support the growing child.

The transition of pediatric Marfan patients to adult care: a challenge and its risks.

BACKGROUND: Care for patients with Marfan syndrome (MFS) has improved substantially in recent decades. Increasing clinical knowledge and genetic analysis allow early diagnosis of the disease in childhood. Because of the earlier initiation to preventive and medical treatment, patients' life expectancy has risen. To ensure optimal care, pediatric patients require a safe follow-up regime, multidisciplinary care, and a safe transition to adult care. METHODS: We collected a sample of 149 pediatric Marfan patients, of whom 34 patients had already been transferred to adult care or who were currently transitioning. First, we evaluated clinical aspects of patients that manifest in childhood and are present in the transition process. Second, we analyzed the transition process itself. RESULTS: We found age-dependent manifestation of organ pathologies. Dilatation of the sinus of Valsalva showed a particularly high prevalence during the transition process and 62% of patients required medical treatment. Mean onset of aortic root dilatation was 9.9±5.8 years. Concerning systemic manifestation in MFS skin striae, wrist and thumb sign, and reduced elbow extension occurred significantly more often in patients who were transitioning than in younger children with MFS. All other clinical Marfan features showed an increased prevalence in patients who were transitioning compared with younger patients. In our cohort, transition was successful in 20 patients (58.9%), 12 patients (35.3%) are still in the transition process and 2 patients (5.9%) were lost to follow up. CONCLUSIONS: Marfan patients in the transition process are already under a chronic disease condition with a high onset of especially cardiovascular pathologies. Although early medical treatment in childhood is effective, the pathologies of the connective tissue require lifelong attention and influence life in many ways. The big challenge during transition is the double change of responsibility from the parents and pediatric doctor to the patient and adult doctor. Consequently, patients in transition process require special attention and close contact with the doctor and the family. A reevaluation by the supervising pediatric Marfan specialist of the successful transition to adult care is indispensable before the pediatric care of Marfan patients is completed.

Kid-Short Marfan Score (Kid-SMS) Is a Useful Diagnostic Tool for Stratifying the Pre-Test Probability of Marfan Syndrome in Childhood.

Due to age dependent organ manifestation, diagnosis of Marfan syndrome (MFS) is a challenge, especially in childhood. It is important to identify children at risk of MFS as soon as possible to direct those to appropriate treatment but also to avoid stigmatization due to false diagnosis. We published the Kid-Short Marfan Score (Kid-SMS) in 2012 to stratify the pre-test probability of MFS in childhood. Hence we now evaluate the predictive performance of Kid-SMS in a new cohort of children. We prospectively investigated 106 patients who were suspected of having MFS. At baseline, children were examined according to Kid-SMS. At baseline and follow-up visit, diagnosis of MFS was established or rejected using standard current diagnostic criteria according to the revised Ghent Criteria (Ghent-2). At baseline 43 patients were identified with a risk of MFS according to Kid-SMS whereas 21 patients had Ghent-2 diagnosis of MFS. Sensitivity was 100%, specificity 77%, negative predictive value 100% and Likelihood ratio of Kid-SMS 4.3. During follow-up period, three other patients with a stratified risk for MFS were diagnosed according to Ghent-2. We confirm very good predictive performance of Kid-SMS with excellent sensitivity and negative predictive value but restricted specificity. Kid-SMS avoids stigmatization due to diagnosis of MFS and thus restriction to quality of life. Especially outpatient pediatricians and pediatric cardiologists can use it for primary assessment.